BGP over QUIC
draft-retana-idr-bgp-quic-04
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Alvaro Retana , Yingzhen Qu , Jeffrey Haas , Shuanglong Chen , Jeff Tantsura | ||
| Last updated | 2024-03-03 | ||
| Replaces | draft-retana-idr-bgp-quic-stream, draft-chen-idr-bgp-over-quic | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Stream | WG state | (None) | |
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-retana-idr-bgp-quic-04
IDR Workgroup A. Retana
Internet-Draft Y. Qu
Intended status: Standards Track Futurewei Technologies
Expires: 4 September 2024 J. Haas
Juniper Networks
S. Chen
Huawei Technologies
J. Tantsura
Nvidia
3 March 2024
BGP over QUIC
draft-retana-idr-bgp-quic-04
Abstract
This document specifies the use of QUIC Streams to support multiple
BGP sessions over one connection in order to achieve high resiliency.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 4 September 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
Retana, et al. Expires 4 September 2024 [Page 1]
Internet-Draft BGP over QUIC Streams March 2024
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Summary of Operations . . . . . . . . . . . . . . . . . . . . 4
4.1. Establish BGP/QUIC Connection . . . . . . . . . . . . . . 4
4.2. Establish BGP/QUIC Control Channel . . . . . . . . . . . 5
4.3. Establish BGP/QUIC Function Channel . . . . . . . . . . . 6
4.4. Channel Reset . . . . . . . . . . . . . . . . . . . . . . 8
4.5. Channel Coordination . . . . . . . . . . . . . . . . . . 8
5. Protocol Definitions . . . . . . . . . . . . . . . . . . . . 8
5.1. BGP Over QUIC Capability . . . . . . . . . . . . . . . . 8
5.2. Capability Category . . . . . . . . . . . . . . . . . . . 10
5.3. Channel Collision Avoidance . . . . . . . . . . . . . . . 11
5.4. BoQ Framing Layer . . . . . . . . . . . . . . . . . . . . 12
5.5. Route Refresh . . . . . . . . . . . . . . . . . . . . . . 13
6. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 14
7. BoQ Finite State Machine (FSM) . . . . . . . . . . . . . . . 15
7.1. Events for the BoQ FSM . . . . . . . . . . . . . . . . . 17
7.1.1. Optional Events . . . . . . . . . . . . . . . . . . . 17
7.1.2. Administrative Events . . . . . . . . . . . . . . . . 21
7.1.3. Timer Events . . . . . . . . . . . . . . . . . . . . 24
7.1.4. QUIC Connection-Based Events . . . . . . . . . . . . 25
7.1.5. QUIC Stream-Based Events . . . . . . . . . . . . . . 26
7.1.6. BGP Message-Based Events . . . . . . . . . . . . . . 27
7.2. Description of FSM . . . . . . . . . . . . . . . . . . . 29
7.2.1. FSM Definition . . . . . . . . . . . . . . . . . . . 29
7.2.1.1. Terms 'active' and 'passive' . . . . . . . . . . 29
7.2.1.2. FSM and Collision Detection . . . . . . . . . . . 29
7.2.1.3. FSM and Optional Channel Attributes . . . . . . . 30
7.2.1.4. FSM Event Numbers . . . . . . . . . . . . . . . . 30
7.2.2. BoQ Finite State Machine . . . . . . . . . . . . . . 30
7.2.2.1. Control Channel FSM . . . . . . . . . . . . . . . 30
7.2.2.2. Function Channel Sending FSM . . . . . . . . . . 52
7.2.2.3. Function Channel Receiving FSM . . . . . . . . . 61
8. Operational Considerations . . . . . . . . . . . . . . . . . 67
8.1. Using Multi-Channel BGP over QUIC . . . . . . . . . . . . 67
8.2. BGP Multi-Channel Prioritization . . . . . . . . . . . . 67
Retana, et al. Expires 4 September 2024 [Page 2]
Internet-Draft BGP over QUIC Streams March 2024
9. Security Considerations . . . . . . . . . . . . . . . . . . . 67
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 68
10.1. UDP Port for BoQ . . . . . . . . . . . . . . . . . . . . 68
10.2. Registration of the BGP4 Identification String . . . . . 69
10.3. BGP Over QUIC Capability . . . . . . . . . . . . . . . . 69
10.4. Error Code . . . . . . . . . . . . . . . . . . . . . . . 70
11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 71
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 71
12.1. Normative References . . . . . . . . . . . . . . . . . . 71
12.2. Informative References . . . . . . . . . . . . . . . . . 72
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 72
1. Introduction
The Border Gateway Protocol (BGP) [RFC4271] is the routing protocol
used to exchange routing and reachability information among
autonomous systems. BGP uses TCP as its transport protocol to
provide reliable communication. BGP establishes peer relationships
between routers using a TCP session on port 179.
The Multiprotocol Extensions for BGP-4 (MP-BGP) [RFC4760] allow BGP
to carry information for multiple Network Layer protocols. However,
only a single TCP connection can reach the Established state between
a pair of peers [RFC4271]. As a consequence, an error related to a
particular Network Layer protocol may result in the termination of
the connection for all.
QUIC [RFC9000] is a UDP-based multiplexed and secure transport
protocol that provides connection-oriented and stateful interaction
between a client and server. It can provide low latency and
encrypted transport with resilient connections.
In QUIC, application protocols exchange information using streams.
Each stream is a separate unidirectional or bidirectional channel
consisting of an ordered stream of bytes. Moreover, each stream has
its own flow control, which limits bytes sent on a stream, together
with flow control of the connection.
This document specifies the procedures for BGP to use QUIC as a
transport protocol with a mechanism to carry Network Layer protocols
(AFI/SAFI) over individual streams. The Network Layer protocols are
identified using a combination of Address Family (AFI) and Subsequent
Address Family (SAFI), as described in [RFC4760]. These per-AFI/SAFI
streams (function channels) and the associated control mechanism
(control channel) for the session are called "BGP channels". In one
BGP over QUIC (BoQ) connection, one control channel and one or more
function channels are used to carry routing information.
Retana, et al. Expires 4 September 2024 [Page 3]
Internet-Draft BGP over QUIC Streams March 2024
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Terminology
BoQ, Multi-channel BGP using QUIC: Running the BGP protocol over
multiple QUIC streams as defined in this document.
QUIC connection: A transport-layer connection between two
endpoints using QUIC [RFC9000].
QUIC streams: A bidirectional or unidirectional bytestream
provided by the QUIC transport [RFC9000].
BGP channel: An instance of a BGP protocol state machine mapped to
a specific QUIC stream.
BGP control channel: A channel dedicated to transmitting the
session control data, which is implemented as a bidirectional
stream.
BGP function channel: A BGP per AFI/SAFI channel, which is
implemented asymmetrically as unidirectional streams.
4. Summary of Operations
4.1. Establish BGP/QUIC Connection
Before two BoQ speakers start exchanging routing information, they
must establish a BGP session. It is established in two phases:
* Establish a transport layer connection. TLS 1.3 is integrated
with QUIC. The TLS authentication parameters used for this
connection are out of the scope of this draft.
* Establish a BoQ session over this transport connection. This
document specifies the details of such an operation.
QUIC connections are established as described in [RFC9000]. During
connection establishment, a BoQ speaker SHOULD use UDP port TBD1 and
MUST select the Application-Layer Protocol Negotiation (ALPN)
[RFC7301] token "boq" in the TLS handshake. Support for other
application-layer protocols MUST NOT be offered in the same
Retana, et al. Expires 4 September 2024 [Page 4]
Internet-Draft BGP over QUIC Streams March 2024
handshake. A connection MUST be closed if the ALPN token is not as
indicated or if other application-layer protocols are offered in the
same handshake.
[RFC4271] defines the operations for a single BGP session between two
BGP speakers using TCP. This document defines the ability to carry
BGP over multiple QUIC streams as "BGP channels".
On a BoQ connection, the BoQ speaker first establishes a
bidirectional stream for the "BGP control channel". The control
channel is used to establish a BGP peer relationship between two BoQ
speakers, similar to RFC 4271. OPEN messages are exchanged on the
control channel, and if the BoQ session parameters are acceptable,
the peering session is established. Similar to RFC 4271, the BoQ
session is terminated with a NOTIFICATION message if the parameters
are unacceptable.
After establishing the control channel, each BoQ speaker may create
function channels using unidirectional QUIC streams. These function
channels are used to carry BGP routes for a specific AFI/SAFI. Only
one function channel per AFI/SAFI can exist from one BoQ speaker to
another (see Section 5.3. Unlike [RFC4271] BGP, there is no
requirement for both BoQ speakers to have a symmetric and matching
set of function channels.
BGP channels largely use the mechanisms of the RFC 4271 Finite State
Machine (FSM) for their establishment. For the control channel
carried over a bidirectional QUIC stream, the FSM is identical to the
RFC 4271 FSM. However, since the function channels are
unidirectional, the RFC 4271 FSM procedures cannot be carried out
solely using the unidirectional channel from one BoQ speaker to
another. Instead, the responding BoQ speaker must carry its replies
for the unidirectional streams over the control channel and address
them to a specific BGP function channel.
4.2. Establish BGP/QUIC Control Channel
After BoQ session establishment, the BoQ speakers will create the
control channel. The control channel is a bidirectional QUIC stream
with stream ID 0 [RFC9000]. It is created by sending a BGP OPEN
message. BGP OPEN messages carry parameters such as the Autonomous
System number, BGP Identifier (router-id), Hold Time, and
Capabilities. These parameters are used by a BoQ speaker to decide
whether a BGP session is permitted to be established.
Retana, et al. Expires 4 September 2024 [Page 5]
Internet-Draft BGP over QUIC Streams March 2024
The capabilities carried in this OPEN message for the control channel
are the BoQ connection-specific parameters; i.e. those that apply to
the entire connection. An example of this is the BGP Role Capability
[RFC9234]. If a function-only capability - as categorized in Table 1
- is included in the OPEN message, it MUST be ignored.
The control channel uses BGP hold time procedures as specified in
[RFC4271]. KEEPALIVE messages are sent periodically in the absence
of other messages on the control channel. If no messages are
received within the negotiated hold time on the control channel, the
BoQ connection is closed with a NOTIFICATION as specified in
Section 6.5 of [RFC4271]. In short, the BoQ control channel is used
to establish the peering relationship and connection parameters
between the two BoQ speakers, ensure connectivity over this session
is verified, and further is used as the response channel for the
function channels as specified in Section 4.3.
It is an error to exchange BGP routing information over the control
channel. This functionality is reserved for the Per-AFI/SAFI
Function channels. If BGP routes are received on the control
channel, the receiving BGP speaker MUST send a BGP NOTIFICATION with
a Cease code on the control channel and close the QUIC connection.
QUIC supports connection migration. However, only the client side
can move. The role of the QUIC endpoints is important. For future
extensibility, a new BoQ Capability indicates the configured role of
the BoQ speaker: Client, Server, or Any. It is expected that the BGP
configuration and QUIC roles match. The QUIC connection can be reset
if they don't. See Section Section 5.1 for details.
4.3. Establish BGP/QUIC Function Channel
Per-AFI/SAFI Function channels are used to exchange routing
information. After the control channel reaches the Established
state, function channels are created as unidirectional QUIC streams
and advertise routes for a single AFI/SAFI using BGP UPDATE messages.
Only one function channel per AFI/SAFI can exist from one BoQ speaker
to another (see Section 5.3).
It is an error to try to establish Per-AFI/SAFI Function channels
prior to the control channel transitioning to the Established state.
Per-AFI/SAFI Function channels SHOULD NOT be permitted to transition
to the Established state prior to the control channel itself entering
the Established state.
BoQ speakers asymmetrically create their function channels. While it
might be the typical case for there to be a symmetric set of per-AFI/
SAFI function channels, one for each speaker, this is not a
Retana, et al. Expires 4 September 2024 [Page 6]
Internet-Draft BGP over QUIC Streams March 2024
requirement. For example, BGP-LS [I-D.ietf-idr-rfc7752bis] may only
require that a BoQ speaker asymmetrically receive BGP-LS NLRI and may
not need to send them.
A BoQ speaker that needs to advertise routes to its peer opens a
unidirectional stream to its neighbor by sending an OPEN message
indicating the particular AFI/SAFI to be used. The BoQ connection-
wide parameters have previously been exchanged over the control
channel. The function channel OPEN messages MUST contain an
identical BGP Autonomous System number and BGP Identifier as the
previously established control channel. It is RECOMMENDED that the
BGP Hold Time value exchanged in the function channels be
significantly longer than the hold time negotiated for the control
channel. It is the responsibility of the hold timer for the control
channel to provide connection verification for the BoQ connection.
The purpose of the function channel negotiated hold time is to
provide verification of the communication between the two BoQ
speakers for that AFI/SAFI.
The BGP Capabilities carried on the function channel SHOULD only be
those that are function-specific, as categorized in Table 1.
Conflicting BoQ connection-wide parameters exchanged over the
function channel MAY result in the BoQ speaker sending a NOTIFICATION
message and not permitting the per-AFI/SAFI function channel to
become Established.
The receiving BoQ speaker replies to those messages as defined in the
[RFC4271] FSM by sending its messages (OPEN/NOTIFICATION/KEEPALIVE)
addressed to the sender over the control channel.
Once the function channel has reached the Established state, BGP
UPDATE messages may be sent to the remote BoQ speaker.
A single function channel for an AFI/SAFI pair results in asymmetric
route advertisements. Both BoQ speakers can create a function
channel to implement symmetric route advertisements.
Each function channel is created independently to naturally support
multi-channel BGP. The neighbor state machines are decoupled; in
case of error, it is possible to reset only one function channel (one
direction of a symmetric route exchange) using a BoQ Error Message
with code BoQ Chanel Reset (see Section 6). If one function channel
is blocked for some reason, other channels can still progress and
operate.
Retana, et al. Expires 4 September 2024 [Page 7]
Internet-Draft BGP over QUIC Streams March 2024
4.4. Channel Reset
A NOTIFICATION is sent over the control channel if the entire BGP
connection needs to be reset for any reason, such as a configuration
change or a network outage. Existing error messages defined by
[RFC4271] and other various extensions SHOULD be used.
If the control channel is closed, the QUIC connection MUST be
terminated using a CONNECTION_CLOSE frame, and an error notification
(see Section 6) should be included to indicate that the connection
has been terminated by BGP. If there are other open channels, they
are also closed when the connection is closed.
A function channel can be reset independently without impacting any
other function channels or the control channel. Please refer to
Section 6.
4.5. Channel Coordination
A single QUIC stream provides ordered and reliable delivery.
However, there is no guarantee of transmission and delivery orders
across streams. Therefore, if specific data from one channel needs
to be received before data from other channels, this requirement must
be accomplished through BGP.
As defined in [RFC9000], a QUIC implementation SHOULD provide ways in
which an application can indicate the relative priority of streams.
A BGP implementation utilizing QUIC as its transport protocol MUST
support a prioritization mechanism for BGP streams. This is
essential for ensuring that critical routing information can be
transmitted with higher priority compared to non-routing information.
How to implement the supported priorities using QUIC congestion
control at the connection level, stream level flow control, and
packetization are out of the scope of this document.
5. Protocol Definitions
5.1. BGP Over QUIC Capability
QUIC supports connection migration. However, only the client side
can move. For a BoQ speaker to take advantage of the QUIC connection
migration capability, it has to be the QUIC client.
Retana, et al. Expires 4 September 2024 [Page 8]
Internet-Draft BGP over QUIC Streams March 2024
For an implementation of the BoQ defined in this document, an
explicit configuration is needed to identify a BoQ speaker's role: a
QUIC client, a QUIC server, or any (Don’t care). The default value
can be "any"; other values MUST be explicitly configured.
A new ”BGP over QUIC” capability is defined below to signal whether
the BoQ speaker is a QUIC client, a QUIC server, or any (Don’t care).
BoQ capability:
Code: TBD2 (to be assigned by IANA)
Length: 1(octet)
Value:
0 Any
1 Client
2 Server
The BoQ Capability is a control-only capability (see Table 1), which
means it SHOULD only be sent in the control channel. It MUST be
ignored if received in the OPEN message of any function channel.
A BoQ session MUST be terminated if the BoQ speaker role
configuration and the QUIC connection role don't match by sending a
NOTIFICATION on the control channel with an error code of BGP over
QUIC Message Error and a Subcode BoQ Capability Mismatch, then
closing the QUIC connection with a CONNECTION_CLOSE frame and an
error code of APPLICATION_ERROR. Please refer to section 19.19 in
[RFC9000] . For example, if a BoQ speaker is configured as a client,
but the QUIC connection comes up as a QUIC server, the QUIC
connection must be terminated. The "any" configuration matches both
the QUIC client and QUIC server roles.
Before initiating a QUIC connection for BGP, the BoQ role
configuration MUST be checked. If a BoQ speaker is configured as a
QUIC client, it MUST try to initiate the QUIC connection. If a BoQ
speaker is configured as a QUIC server, it MUST wait for a QUIC
connection.
The following collision avoidance procedure SHOULD be followed during
QUIC connection setup:
When one BoQ speaker is configured as a client, and the other side
is configured as a server, no collision will happen. If the other
side initiates a QUIC connection, a QUIC CONNECTION_CLOSE frame
with error code APPLICATION_ERROR MUST be sent.
When a BoQ speaker is configured as "any" or as a server, it MUST
accept the QUIC connection initiated by the other BoQ speaker.
Retana, et al. Expires 4 September 2024 [Page 9]
Internet-Draft BGP over QUIC Streams March 2024
During the control channel setup, the BoQ capability MUST be checked
to make sure the configured BoQ role matches the QUIC connection.
When both BoQ peers are configured as "any", the session collision
mechanism defined in [RFC6286] and [RFC4271] MUST be followed.
In case there is a BoQ role mismatch, for example, a BoQ speaker
configured as "any" accepted a QUIC connection from a BoQ speaker
configured as server, an error notification, BoQ Capability Mismatch,
SHOULD be sent and the connection MUST be terminated. Please refer
to Section 6 for details.
5.2. Capability Category
For existing BGP capabilities, some of of them apply to the entire
connection and MUST be sent in the control channel OPEN message, such
as the BGP Role defined in [RFC9234]. If such capabilities are sent
in an OPEN message in a function channel, they MUST be ignored.
The following table shows the category of each capability.
+=======+=======================+=================+============+
| Value | Name | Ref | Control/ |
| | | | Function |
+=======+=======================+=================+============+
| 1 | Multiprotocol | RFC2858 | F |
| | Extensions for BGP-4 | | |
+-------+-----------------------+-----------------+------------+
| 2 | Route Refresh | RFC2918 | F |
| | Capability for BGP-4 | | |
+-------+-----------------------+-----------------+------------+
| 3 | Outbound Route | RFC5291 | F |
| | Filtering Capability | | |
+-------+-----------------------+-----------------+------------+
| 5 | Extended Next Hop | RFC8950 | F |
| | Encoding | | |
+-------+-----------------------+-----------------+------------+
| 6 | BGP Extended Message | RFC8654 | C/F |
+-------+-----------------------+-----------------+------------+
| 7 | BGPsec Capability | RFC8205 | C/F |
+-------+-----------------------+-----------------+------------+
| 8 | Multiple Labels | RFC8277 | C - |
| | Capability | | deprecated |
+-------+-----------------------+-----------------+------------+
| 9 | BGP Role | RFC9234 | C |
+-------+-----------------------+-----------------+------------+
| 64 | Graceful Restart | RFC4724 | C/F |
| | Capability | | |
+-------+-----------------------+-----------------+------------+
Retana, et al. Expires 4 September 2024 [Page 10]
Internet-Draft BGP over QUIC Streams March 2024
| 65 | Support for 4-octet | RFC6793 | C/F |
| | AS number capability | | |
+-------+-----------------------+-----------------+------------+
| 67 | Support for Dynamic | draft-ietf-idr- | C/F |
| | Capability | dynamic-cap | |
| | (capability specific) | | |
+-------+-----------------------+-----------------+------------+
| 68 | Multisession BGP | draft-ietf-idr- | Not |
| | Capability | bgp- | compatible |
| | | multisession | |
+-------+-----------------------+-----------------+------------+
| 69 | ADD-PATH Capability | RFC7911 | F |
+-------+-----------------------+-----------------+------------+
| 70 | Enhanced Route | RFC7313 | F |
| | Refresh Capability | | |
+-------+-----------------------+-----------------+------------+
| 71 | Long-Lived Graceful | draft-uttaro- | C/F |
| | Restart (LLGR) | idr-bgp- | |
| | Capability | persistence | |
+-------+-----------------------+-----------------+------------+
| 72 | Routing Policy | draft-ietf-idr- | F |
| | Distribution | rpd | |
+-------+-----------------------+-----------------+------------+
| 73 | FQDN Capability | draft-walton- | C |
| | | bgp-hostname- | |
| | | capability | |
+-------+-----------------------+-----------------+------------+
| 74 | BFD Capability | draft-ietf-idr- | C |
| | | bgp-bfd-strict- | |
| | | mode | |
+-------+-----------------------+-----------------+------------+
| 75 | Software Version | draft-abraitis- | C/F |
| | Capability | bgp-version- | |
| | | capability | |
+-------+-----------------------+-----------------+------------+
Table 1: Capability Category Table
5.3. Channel Collision Avoidance
A function channel for a specific Network layer protocol MUST NOT be
created if one already exists.
If a BoQ speaker receives a function channel creation request for an
AFI/SAFI that already exists, the local BoQ speaker SHOULD send a
notification with Error Code BoQ and subcode BoQ Channel Conflict
through the control channel, and upon receiving this notification the
channel initiator MUST terminate the channel.
Retana, et al. Expires 4 September 2024 [Page 11]
Internet-Draft BGP over QUIC Streams March 2024
If a BoQ speaker receives a functional channel creation request for
an AFI/SAFI that it doesn't support, the local BoQ speaker SHOULD
send a notification using existing subcode "Unsupported AFI/SAFI" in
the OPEN Message Error BGP NOTIFICATION message.
Unless allowed via configuration, a channel collision with an
existing BGP channel in the Established state causes the closing of
the newly created channel.
5.4. BoQ Framing Layer
In version 1 of QUIC, BoQ messages are carried by QUIC STREAM frames.
In BoQ, the control channel always uses QUIC stream 0, which is a
client-initiated bidirectional stream. Function channels, which are
unidirectional streams, can be client or server initiated.
Some BoQ messages, although sent in the control channel, are meant
for a function channel, such as the responding OPEN message or
KEEPALIVE message for a function channel. These messages need to
carry the corresponding function channel/stream ID information.
There are two types of BoQ Frames: Data and Control Data.
Data frames have the following format:
BoQ Data Frame Format {
Type (16) = 0,
Length (16),
Frame Payload (...)
}
Control Data Frames have the following format:
BoQ Control Data Frame Format {
Type (16) = 1,
Length (16),
Stream ID (62),
padding (2) = 0,
Frame Payload (...)
}
Type: two octets, identifying the frame type.
Length: The two-byte unsigned integer that describes the length in
bytes of the frame payload.
Stream ID: A 62-bit integer indicating the receiving stream ID of
this message.
Retana, et al. Expires 4 September 2024 [Page 12]
Internet-Draft BGP over QUIC Streams March 2024
Frame Payload: BGP messages.
The following table lists the frame type to be used when BGP messages
are sent in different channels.
+===============+=================+=====================+
| | Control Channel | Function Channel |
+===============+=================+=====================+
| OPEN | Control Data | Data |
+---------------+-----------------+---------------------+
| UPDATE | / | Data |
+---------------+-----------------+---------------------+
| KEEPALIVE | Control Data | Data |
+---------------+-----------------+---------------------+
| NOTIFICATION | Control Data | Data |
+---------------+-----------------+---------------------+
| Route-Refresh | Control Data | Data (subtype 1, 2) |
+---------------+-----------------+---------------------+
Table 2: BoQ Frame Type Mapping
An OPEN message sent in the control channel for the control channel
creation MUST NOT contain Multiprotocol Extensions Capability (value
1) in the Capabilities. An OPEN message sent in a function channel
and the responding OPEN message sent in the control channel for one
AFI/SAFI MUST contain only one Multiprotocol Extensions Capability
(value 1) in the Capabilities.
There is no UPDATE message sent in the control channel.
For the KEEPALIVE and NOTIFICATION messages sent in the control
channel for one function channel, the BoQ Control Data frame MUST be
used, and the stream ID in the frame is to indicate the the target
AFI/SAFI.
Route-refresh messages are sent in the control channel and function
channels. Please refer to Section 5.5 for details.
5.5. Route Refresh
BGP Route Refresh messages are defined in [RFC2918] and [RFC7313].
When two BoQ peers with the enhanced route refresh capability, wish
to initiate a route refresh from one peer to another, the initiating
speaker MUST send a ROUTE-REFRESH message with subtype 0 in its
control channel with the stream ID set to the corresponding AFI/SAFI.
Retana, et al. Expires 4 September 2024 [Page 13]
Internet-Draft BGP over QUIC Streams March 2024
When starting a route refresh for a specific AFI/SAFI, whether
initiated locally or in response to a route refresh request from the
peer, a BoQ speaker MUST send a beginning of a route refresh (BoRR)
message in the function channel. After the re-advertisement of the
route entries it MUST send an ending of a route refresh (EoRR)
message in the function channel.
If only the route refresh capability defined in [RFC2918] is
supported, but not the enhanced route refresh capability defined in
[RFC7313], a BoQ speaker MUST send the route refresh request message
in the control channel.
6. Error Handling
OPEN message error handling is defined in section 6.2 of [RFC4271].
This document defines a new NOTIFCATION error code:
Error Code Name
TBD BoQ Message Error
The following error subcode is defined as well:
Subcode Name
1 BoQ Capability Mismatch
2 BoQ Connection Reset
3 BoQ Channel Reset
4 BoQ Channel Conflict
BoQ Capability Mismatch is sent when a BoQ speaker's configured role
doesn't match the QUIC connection, and the connection MUST be
terminated after sending this notification. Details are described in
Section 5.1.
For a BoQ speaker, BGP UPDATE messages are only sent in function
channels. If there is any error detected when processing an UPDATE
message, a NOTIFICATION MUST be sent in the control channel with the
error subcode and function channel stream ID. The function channel
SHOULD be terminated upon receiving the NOTIFICATION message. The
error checking process specified in Section 6.2 of [RFC4271] SHOULD
be followed.
The error handling specified in this section is applicable for a BoQ
speaker implementing this document.
Any individual BGP channel can be terminated as specified in
[RFC4486].
Retana, et al. Expires 4 September 2024 [Page 14]
Internet-Draft BGP over QUIC Streams March 2024
7. BoQ Finite State Machine (FSM)
The data structures and FSM described in this document are conceptual
and do not have to be implemented precisely as described here, as
long as the implementations support the described functionality and
they exhibit the same externally visible behavior.
A BoQ implementation is expected to maintain a separate FSM for each
channel. The control channel in a BoQ connection is required to
reach the Established state before any function channel can be
created. This means the setup of the QUIC connection and any related
errors are processed by the control channel.
The BGP messages and events handled by the control and function
channels vary. In general, what is specified in [RFC4271] section 8
that applies to a BGP peer connection is applicable to a BoQ channel
unless explicitly specified in this document.The BoQ FSM defined in
this section is to replace section 8 of [RFC4271].
RFC 4271 section 8 defines the mandatory and optional session
attributes for each connection. For a BoQ implementation, some of
these attributes are applicable to both the control and function
channels. However some attributes only apply to the control or
function channels. Also, since the function channels in BoQ are
unidirectional, the FSMs are different for the function channel
sending side and receiving side. The following tables list the
applicability of each attribute.
Table 3 lists the mandatory attributes required for each channel.
Retana, et al. Expires 4 September 2024 [Page 15]
Internet-Draft BGP over QUIC Streams March 2024
+=====================+=========+=================+===========+
| Channel Attributes | Control | Function | Function |
| | Channel | Channel Sending | Channel |
| | | | Receiving |
+=====================+=========+=================+===========+
| State | Y | Y | Y |
+---------------------+---------+-----------------+-----------+
| ConnectRetryCounter | Y | Y | N |
+---------------------+---------+-----------------+-----------+
| ConnectRetryTimer | Y | Y | N |
+---------------------+---------+-----------------+-----------+
| ConnectRetryTime | Y | Y | N |
+---------------------+---------+-----------------+-----------+
| HoldTimer | Y | Y | Y |
+---------------------+---------+-----------------+-----------+
| HoldTime | Y | Y | Y |
+---------------------+---------+-----------------+-----------+
| KeepaliveTimer | Y | Y | Y |
+---------------------+---------+-----------------+-----------+
| KeepaliveTime | Y | Y | Y |
+---------------------+---------+-----------------+-----------+
| StreamID | N | Y | Y |
+---------------------+---------+-----------------+-----------+
Table 3: BoQ Mandatory Channel Attributes
The state channel attribute indicated the current state of the BoQ
FSM. The ConnectRetryCounter indicates the number of times a BoQ
speaker has tried to establish a channel with its peer. For a BoQ
function channel, a new mandatory attribute StreamID is required.
This attribute indicates the QUIC Stream ID used by the function
channel.
The optional channel attributes are in Table 4. These optional
attributes may be supported in a channel if it is indicated as "Y"
for a channel in the table.
Retana, et al. Expires 4 September 2024 [Page 16]
Internet-Draft BGP over QUIC Streams March 2024
+====================================+=======+========+===========+
| Optional Channel Attributes |Control|Function| Function |
| |Channel|Channel | Channel |
| | |Sending | Receiving |
+====================================+=======+========+===========+
| AcceptConnectionsUnconfiguredPeers |Y |N | N |
+------------------------------------+-------+--------+-----------+
| AllowAutomaticStart |Y |Y | N |
+------------------------------------+-------+--------+-----------+
| AllowAutomaticStop |Y |Y | N |
+------------------------------------+-------+--------+-----------+
| CollisionDetectEstablishedState |Y |N | N |
+------------------------------------+-------+--------+-----------+
| DampPeerOscillations |Y |Y | N |
+------------------------------------+-------+--------+-----------+
| DelayOpen |Y |N | N |
+------------------------------------+-------+--------+-----------+
| DelayOpenTime |Y |N | N |
+------------------------------------+-------+--------+-----------+
| DelayOpenTimer |Y |N | N |
+------------------------------------+-------+--------+-----------+
| IdleHoldTime |Y |Y | N |
+------------------------------------+-------+--------+-----------+
| IdleHoldTimer |Y |Y | N |
+------------------------------------+-------+--------+-----------+
| PassiveQUICEstablishment |Y |N | N |
+------------------------------------+-------+--------+-----------+
| SendNOTIFICATIONwithoutOPEN |Y |N | Y |
+------------------------------------+-------+--------+-----------+
| TrackQUICState |Y |N | N |
+------------------------------------+-------+--------+-----------+
Table 4: BoQ Optional Channel Attributes
7.1. Events for the BoQ FSM
7.1.1. Optional Events
The Inputs to the BoQ FSM are events. Events can either be mandatory
or optional. Some optional events are linked to optional channel
attributes. Optional channel attributes enable several groups of FSM
functionality.
The linkage between FSM functionality, events, and the optional
session attributes are as described in RFC4271, Section 8.1.1. Any
updates of deviations are indicated below, and the applicability is
summarized in the tables above.
Retana, et al. Expires 4 September 2024 [Page 17]
Internet-Draft BGP over QUIC Streams March 2024
Group 1: Automatic Administrative Events (start/Stop)
Optional Channel Attributes: AllowAutomaticStart,
AllowAutomaticStop, DampPeerOscillations, IdleHoldTime,
IdleHoldTimer
Option 1: AllowAutomaticStart
Description: A BoQ channel connection can be started and stopped
by administrative control. This administrative control can
either be manual, based on operator intervention, or under the
control of logic that is specific to a BoQ implementation. The
term "automatic" refers to a start being issued to the BoQ
channel FSM when such logic determines that the BoQ channel
should be restarted.
The AllowAutomaticStart attribute specifies that this BoQ
channel supports automatic starting of the BoQ channel.
If a BoQ implementation supports AllowAutomaticStart, a channel
may be repeatedly restarted. Three other options control the
rate at which the automatic restart occurs:
DampPeerOscillations, IdleHoldTime, and the IdleHoldTimer.
The DampPeerOscillations option specifies that the
implementation engages additional logic to damp the
oscillations of BoQ channels in the face of sequences of
automatic start and automatic stop. IdleHoldTime specifies the
length of time the BGP peer is held in the Idle state prior to
allowing the next automatic restart. The IdleHoldTimer is the
timer that holds the peer in Idle state.
Values: TRUE or FALSE
Option 2: AllowAutomaticStart
Description: This BoQ channel optional attribute indicates that
the channel allows "automatic" stopping of the BoQ channel. An
"automatic" stop is defined as a stop under the control of
implementation-specific logic. The implementation-specific
logic is outside the scope of this specification.
Values: TRUE or FALSE
Option 3: DampPeerOscillations
Description: The DampPeerOscillations optional channel attribute
indicates that the BoQ channel connection is using logic that
damps BGP peer oscillations in the Idle State.
Retana, et al. Expires 4 September 2024 [Page 18]
Internet-Draft BGP over QUIC Streams March 2024
Values: TRUE or FALSE
Option 4: IdleHoldTime
Description: The IdleHoldTime is the value that is set in the
IdleHoldTimer.
Values: Time in seconds
Option 5: IdleHoldTimer
Description: The IdleHoldTimer aids in controlling BGP peer
oscillation. The IdleHoldTimer is used to keep the BGP peer in
Idle for a particular duration. The IdleHoldTimer_Expires
event is described in Section 7.1.3.
Values: Time in seconds
Group 2: Unconfigured Peers
Optional Channel Attributes: AcceptConnectionsUnconfiguredPeers
Option 1: AcceptConnectionsUnconfiguredPeers
Description: The BoQ FSM optionally allows the acceptance of BoQ
peer connections from neighbors that are not pre-configured.
The "AcceptConnectionsUnconfiguredPeers" optional channel
attribute allows the FSM to support the state transitions that
allow the implementation to accept or reject these unconfigured
peers and is only applicable to the control channel.
The AcceptConnectionsUnconfiguredPeers has security
implications. Please refer to the BGP Vulnerabilities document
[RFC4272] for details.
Values: TRUE or FALSE
Group 3: QUIC processing
Optional Channel Attributes: PassiveQUICEstablishment,
TrackQUICState
Option 1: PassiveQUICEstablishment
Description: This option indicates that the BoQ FSM will
Retana, et al. Expires 4 September 2024 [Page 19]
Internet-Draft BGP over QUIC Streams March 2024
passively wait for the remote BGP peer to establish the BGP
QUIC connection. As specified in Section 5.1, a BoQ speaker's
role can be a QUIC client, a QUIC server, or any. If a BoQ
speaker is configured as a QUIC client, the
PassiveQUICEstablishment MUST be set to FALSE; when a BoQ
speaker is configured as a QUIC server, the
PassiveQUICEstablishment MUST be set to TRUE.
Values: TRUE or FALSE
Option 2: TrackQUICState
Description: The BoQ FSM normally tracks the end result of a QUIC
connection attempt rather than individual QUIC messages.
Optionally, the BoQ FSM can support additional interaction with
the QUIC connection negotiation. The interaction with the QUIC
events may increase the amount of logging the BGP peer
connection requires and the number of BoQ FSM changes.
Values: TRUE or FALSE
Group 4: BGP Message Processing
Optional Session Attributes: DelayOpen, DelayOpenTime,
DelayOpenTimer, SendNOTIFICATIONwithoutOPEN,
CollisionDetectEstablishedState
Option 1: DelayOpen
Description: The DelayOpen optional channel attribute allows
implementations to be configured to delay sending an OPEN
message for a specific time period (DelayOpenTime). The delay
allows the remote BGP Peer time to send the first OPEN message.
Values: TRUE or FALSE
Option 2: DelayOpenTime
Description: The DelayOpenTime is the initial value set in the
DelayOpenTimer.
Values: Time in seconds
Option 3: DelayOpenTimer
Description: The DelayOpenTimer optional channel attribute is
used to delay the sending of an OPEN message on a channel. The
DelayOpenTimer_Expires event (Event 12) is described in
Section 7.1.3.
Retana, et al. Expires 4 September 2024 [Page 20]
Internet-Draft BGP over QUIC Streams March 2024
Values: Time in seconds
Option 4: SendNOTIFICATIONwithoutOPEN
Description: The SendNOTIFICATIONwithoutOPEN allows a peer to
send a NOTIFICATION without first sending an OPEN message.
Without this optional channel attribute, the BGP connection
assumes that an OPEN message must be sent by a peer prior to
the peer sending a NOTIFICATION message.
Values: TRUE or FALSE
Option 5: CollisionDetectEstablishedState
Description: This optional channel attribute indicates that this
BGP connection processes collisions in the Established state.
Values: TRUE or FALSE
7.1.2. Administrative Events
An administrative event is an event in which the operator interface
and BGP Policy engine signal the BoQ FSM to start or stop the BGP
state machine. The basic start and stop indications are augmented by
optional connection attributes that signal a certain type of start or
stop mechanism to the BoQ FSM.
Note that only Event 1 (ManualStart) and Event 2 (ManualStop) are
mandatory administrative events. All other administrative events are
optional (Events 3-8). Each event below has a name, definition,
status (mandatory or optional), and the optional channel attributes
that SHOULD be set at each stage. When generating Event 1 through
Event 8 for the BoQ FSM, the conditions specified in the "Optional
Attribute Status" section are verified. If any of these conditions
are not satisfied, then the local system should log an FSM error.
The settings of optional channel attributes may be implicit in some
implementations, and therefore may not be set explicitly by an
external operator action. The administrative states described below
may also be implicit in some implementations and not directly
configurable by an external operator.
Event 1: ManualStart
Definition: Local system administrator manually starts a BoQ
channel. For the control channel, this event indicates the
start of the QUIC connection and the control channel. For a
function channel, it is to start an unidirectional channel to
the BoQ peer.
Retana, et al. Expires 4 September 2024 [Page 21]
Internet-Draft BGP over QUIC Streams March 2024
Status: Mandatory
Optional Attribute Status: For the control channel, the
PassiveQUICEstablishment attribute SHOULD be set to FALSE.
Event 2: ManualStop
Definition: Local system administrator manually stops a BoQ
channel. For the control channel, this event indicates the end
of the BoQ connection.
Status: Mandatory
Optional Attribute Status: No interaction with any optional
attributes.
Event 3: AutomaticStart
Definition: Local system automatically starts a BoQ channel. For
the control channel, this event indicates the start of the QUIC
connection and the control channel. For a function channel, it
is to start an unidirectional channel to the BoQ peer.
Status: Optional
Optional Attribute Status: 1) The AllowAutomaticStart attribute
SHOULD be set to TRUE if this event occurs.
2) If the PassiveQUICEstablishment optional session attribute
is supported, it SHOULD be set to FALSE.
3) If the DampPeerOscillations optional session attribute is
supported, it SHOULD be set to FALSE when this event occurs.
Event 4: ManualStart_with_PassiveQUICEstablishment
Definition: Local system administrator manually starts the peer
connection, but has PassiveQUICEstablishment enabled. The
PassiveQUICEstablishment optional attribute indicates that the
peer will listen prior to establishing the connection. This
event only applies to the control channel.
Status: Optional
Optional Attribute Status: 1) The PassiveQUICEstablishment
attribute SHOULD be set to TRUE if this event occurs.
2) The DampPeerOscillations attribute SHOULD be set to FALSE
when this event occurs.
Event 5: AutomaticStart_with_PassiveQUICEstablishment
Retana, et al. Expires 4 September 2024 [Page 22]
Internet-Draft BGP over QUIC Streams March 2024
Definition: Local system automatically starts the BGP connection
with the PassiveQUICEstablishment enabled. The
PassiveQUICEstablishment optional attribute indicates that the
peer will listen prior to establishing a connection. This
event only applies to the control channel.
Status: Optional
Optional Attribute Status: 1) The AllowAutomaticStart attribute
SHOULD be set to TRUE.
2) The PassiveTcpEstablishment attribute SHOULD be set to TRUE.
3) If the DampPeerOscillations attribute is supported, the
DampPeerOscillations SHOULD be set to FALSE.
Event 6: AutomaticStart_with_DampPeerOscillations
Definition: Local system automatically starts the BGP peer
connection with peer oscillation damping enabled. The exact
method of damping persistent peer oscillations is determined by
the implementation and is outside the scope of this document.
Status: Optional
Optional Attribute Status: 1) The AllowAutomaticStart attribute
SHOULD be set to TRUE.
2) The DampPeerOscillations attribute SHOULD be set to TRUE.
3) The PassiveQUICEstablishment attribute SHOULD be set to
FALSE.
Event 7: AutomaticStart_with_DampPeerOscillations_and_PassiveQUICE
stablishment
Definition: Local system automatically starts the BGP peer
connection with peer oscillation damping enabled and
PassiveQUICEstablishment enabled. The exact method of damping
persistent peer oscillations is determined by the
implementation and is outside the scope of this document. This
event only applies to the control channel.
Status: Optional
Optional Attribute Status: 1) The AllowAutomaticStart attribute
SHOULD be set to TRUE.
2) The DampPeerOscillations attribute SHOULD be set to TRUE.
Retana, et al. Expires 4 September 2024 [Page 23]
Internet-Draft BGP over QUIC Streams March 2024
3) The PassiveQUICEstablishment attribute SHOULD be set to
TRUE.
Event 8: AutomaticStop
Definition: Local system automatically stops a BoQ channel. For
the control channel, this event indicates the end of the BoQ
connection.
An example of an automatic stop event for a function channel is
exceeding the number of prefixes for a given peer and the local
system automatically disconnecting the peer.
Status: Optional
Optional Attribute Status: 1) The The AllowAutomaticStop
attribute SHOULD be TRUE.
7.1.3. Timer Events
Event 9: ConnectRetryTimer_Expires
Definition: An event generated when the ConnectRetryTimer
expires.
Status: Mandatory
Event 10: HoldTimer_Expires
Definition: An event generated when the HoldTimer expires.
Status: Mandatory
Event 11: KeepaliveTimer_Expires
Definition: An event generated when the KeepaliveTimer expires.
Status: Mandatory
Event 12: DelayOpenTimer_Expires
Definition: An event generated when the DelayOpenTimer expires.
Status: Optional
Optional Attribute Status: If this even occurs,
1) DelayOpen attribute SHOULD be set to TRUE,
2) DelayOpenTime attribute SHOULD be supported,
3) DelayOpenTimer SHOULD be supported.
Retana, et al. Expires 4 September 2024 [Page 24]
Internet-Draft BGP over QUIC Streams March 2024
Event 13: IdleHoldTimer_Expires
Definition: An event generated when the IdleHoldTimer expires,
indicating that the BoQ connection has completed waiting for
the back-off period to prevent BGP peer oscillation.
The IdleHoldTimer is only used when the persistent peer
oscillation damping function is enabled by setting the
DampPeerOscillations optional attribute to TRUE.
Implementations not implementing the persistent peer
oscillation damping function may not have the IdleHoldTimer.
Status: Optional
Optional Attribute Status: If this even occurs,
1) DampPeerOscillations attribute SHOULD be set to TRUE.
2) IdleHoldTimer SHOULD have just expired.
7.1.4. QUIC Connection-Based Events
Event 14: QUICConnection_Valid
Definition: Event indicating the local system reception of a QUIC
connection request with a valid source IP address, UDP port,
destination IP address, and UDP Port. The definition of
invalid source and invalid destination IP address is determined
by the implementation.
BoQ's destination port SHOULD be port TDB1 (Section 4.1).
A QUIC connection request is denoted by the local system
receiving the QUIC Initial packet [RFC9000]. This event only
applies to the control channel.
Status: Optional
Optional Attribute Status: The TrackQUICState attribute SHOULD be
set to TRUE if this event occurs.
Event 15: QUIC_CR_Invalid
Definition: Event indicating the local system reception of a QUIC
connection request with either an invalid source address or
port number, or an invalid destination address or port number.
BoQ's destination port SHOULD be port TDB1 (Section 4.1).
Retana, et al. Expires 4 September 2024 [Page 25]
Internet-Draft BGP over QUIC Streams March 2024
A QUIC connection request is denoted by the local system
receiving the QUIC Initial packet [RFC9000]. This event only
applies to the control channel.
Status: Optional
Optional Attribute Status: The TrackQUICState attribute SHOULD be
set to TRUE if this event occurs.
Event 16: QUIC_CR_Acked
Definition: Event indicating the local system's request to
establish a QUIC connection to the remote peer has been
completed.
The local system's QUIC connection request has completed and a
HANDSHAKE_DONE frame is received [RFC9000]. This event only
applies to the control channel.
Status: Mandatory
Event 17: QUICConnectionConfirmed
Definition: Event indicating that the local system has received a
confirmation that the QUIC connection has been established by
the remote site.
The HANDSHAKE_DONE frame has been acknowledged [RFC9000]. This
event only applies to the control channel.
Status: Mandatory
Event 18: QUICConnectionFails
Definition: Event indicating that the local system has received a
QUIC connection failure notice. This event only applies to the
control channel.
Status: Mandatory
7.1.5. QUIC Stream-Based Events
Event 29: QUICStreamOpen
Definition: Event indicating that the local system's request to
open a QUIC stream to the remote peer has been completed.
Status: Mandatory
Event 30: QUICStreamClose
Definition: Event indicating that the local system has received a
Retana, et al. Expires 4 September 2024 [Page 26]
Internet-Draft BGP over QUIC Streams March 2024
QUIC stream close notice. The event needs to include a
StreamID to identify the stream closed.
Status: Mandatory
7.1.6. BGP Message-Based Events
Event 19: BGPOpen
Definition: An event is generated when a valid OPEN message has
been received.
Status: Mandatory
Optional Attribute Status: 1) The DelayOpen optional attribute
SHOULD be set to FALSE.
2) The DelayOpenTimer SHOULD not be running.
Event 20: BGPOpen with DelayOpenTimer running
Definition: An event is generated when a valid OPEN message has
been received for a peer that has a successfully established
transport connection and is currently delaying the sending of a
BGP open message.
Status: Optional
Optional Attribute Status: 1) The DelayOpen attribute SHOULD be
set to TRUE.
2) The DelayOpenTimer SHOULD be running.
Event 21: BGPHeaderErr
Definition: An event is generated when a received BGP message
header is not valid.
Status: Mandatory
Event 22: BGPOpenMsgErr
Definition: An event is generated when an OPEN message has been
received with errors.
Status: Mandatory
Event 23: OpenCollisionDump
Definition: An event generated administratively when a connection
Retana, et al. Expires 4 September 2024 [Page 27]
Internet-Draft BGP over QUIC Streams March 2024
collision has been detected while processing an incoming OPEN
message and this connection has been selected to be
disconnected. See Section 5.3 in this document and Section 6.8
in [RFC4271] for more information on collision detection.
Event 23 is an administrative action generated by
implementation logic that determines whether this connection
needs to be dropped per the rules in Section 5.3 in this
document and Section 6.8 in [RFC4271].
Status: Optional
Optional Attribute Status: If the state machine is to process
this event in the Established state,
1) CollisionDetectEstablishedState optional attribute SHOULD be
set to TRUE.
Please note: The OpenCollisionDump event can occur in Idle,
Connect, Active, OpenSent, and OpenConfirm without any optional
attributes being set.
Event 24: NotifMsgVerErr
Definition: An event is generated when a NOTIFICATION message
with "version error" is received.
Status: Mandatory
Event 25: NotifMsg
Definition: An event is generated when a NOTIFICATION message is
received and the error code is anything but "version error".
Status: Mandatory
Event 26: KeepAliveMsg
Definition: An event is generated when a KEEPALIVE message is
received.
Status: Mandatory
Event 27: UpdateMsg
Definition: An event is generated when a valid UPDATE message is
received.
Status: Mandatory
Event 28: UpdateMsgErr
Definition: An event is generated when an invalid UPDATE message
Retana, et al. Expires 4 September 2024 [Page 28]
Internet-Draft BGP over QUIC Streams March 2024
is received.
Status: Mandatory
7.2. Description of FSM
7.2.1. FSM Definition
BoQ implementations are expected to maintain a separate FSM for each
BoQ channel. As described later in this section, a BoQ
implementation will have one FSM for the control channel, plus one
FSM for each direction of a function channel. For example, two BoQ
speakers configured to advertise IPv6 routes in both directions will
have 3 active FSMs: one for the control channel, and one for each
direction (send and receive) of the IPv6 route exchange. One BoQ FSM
corresponds to one QUIC stream connection.
A BoQ implementation MUST connect to and listen on UDP port TBD1 for
incoming connections in addition to trying to connect to peers.
There exists a period in which the identity of the peer on the other
end of an incoming connection is known, but the BGP identifier is not
known. During this time, both an incoming and outgoing connection
may exist for the same configured peering. This is referred to as a
connection collision (see Section 6.8 of [RFC4271]).
7.2.1.1. Terms 'active' and 'passive'
There is only one active side and one passive side to any one QUIC
connection. In BGP over TCP, it doesn't matter which end is active
and which is passive. Differently in BoQ, the distinction is
significant and they correspond to the QUIC client and server roles.
Refer to Section 5.1 for more details.
7.2.1.2. FSM and Collision Detection
There is one control channel FSM per BoQ connection. When a
connection collision occurs prior to determining what peer a
connection is associated with, there may be two connections for one
peer. Connection collisions are resolved using the specification in
Section 6.8 of [RFC4271]. After the connection collision is
resolved, the FSM for the connection that is closed SHOULD be
disposed.
Retana, et al. Expires 4 September 2024 [Page 29]
Internet-Draft BGP over QUIC Streams March 2024
7.2.1.3. FSM and Optional Channel Attributes
Optional Channel Attributes specify either attributes that act as
flags (TRUE or FALSE) or optional timers. For optional attributes
that act as flags, if the optional channel attribute can be set to
TRUE on the system, the corresponding BoQ FSM actions must be
supported. For example, if the following options can be set in a BoQ
implementation: AutoStart and PassiveQUICEstablishment, then Events
3, 4 and 5 must be supported. If an optional channel attribute
cannot be set to TRUE, the events supporting that set of options do
not have to be supported.
Each of the optional timers (DelayOpenTimer and IdleHoldTimer) has a
group of attributes that are:
- flag indicating support,
- Time set in Timer,
- Timer.
The two optional timers show this format:
DelayOpenTimer: DelayOpen, DelayOpenTime, DelayOpenTimer
IdleHoldTimer: DampPeerOscillations, IdleHoldTime, IdleHoldTime
If the flag indicating support for an optional timer (DelayOpen or
DampPeerOscillations) cannot be set to TRUE, the timers and events
supporting that option do not have to be supported.
7.2.1.4. FSM Event Numbers
Same as [RFC4271], the Event numbers (1-30) utilized in this state
machine description aid in specifying the behavior of the BGP state
machine. Note event 29 and 30 are defined in this document.
Implementations MAY use these numbers to provide network management
information. The exact form of an FSM or the FSM events are specific
to each implementation.
7.2.2. BoQ Finite State Machine
7.2.2.1. Control Channel FSM
Idle State:
Initially, the control channel FSM is in the Idle state.
Retana, et al. Expires 4 September 2024 [Page 30]
Internet-Draft BGP over QUIC Streams March 2024
In this state, the control channel FSM refuses all incoming BGP
connections for this peer. No resources are allocated to the
peer. In response to a ManualStart event (Event 1) or an
AutomaticStart event (Event 3), the local system:
* initializes all BGP resources for the peer connection,
* sets ConnectRetryCounter to zero,
* starts the ConnectRetryTimer with the initial value,
* initiates a QUIC connection to the other BGP peer if the local
system is configured as BoQ client or any,
* listens for a connection that may be initiated by the remote
BGP peer if the local system is not configured as BoQ client,
and
* changes its state to Connect.
The ManualStop event (Event 2) and AutomaticStop (Event 8) event
are ignored in the Idle state.
In response to a ManualStart_with_PassiveQUICEstablishment event
(Event 4) or AutomaticStart_with_PassiveQUICEstablishment event
(Event 5), the local system:
* initializes all BGP resources,
* sets the ConnectRetryCounter to zero,
* starts the ConnectRetryTimer with the initial value,
* listens for a connection that may be initiated by the remote
peer, and
* changes its state to Active.
The exact value of the ConnectRetryTimer is a local matter, but it
SHOULD be sufficiently large to allow QUIC initialization.
If the DampPeerOscillations attribute is set to TRUE, the
following three additional events may occur within the Idle state:
* AutomaticStart_with_DampPeerOscillations (Event 6),
* AutomaticStart_with_DampPeerOscillations_and_
PassiveQUICEstablishment (Event 7),
Retana, et al. Expires 4 September 2024 [Page 31]
Internet-Draft BGP over QUIC Streams March 2024
* IdleHoldTimer_Expires (Event 13).
Upon receiving these 3 events, the local system will use these
events to prevent peer oscillations. The method of preventing
persistent peer oscillation is outside the scope of this document.
Any other event (Events 9-12, 15-30) received in the Idle state
does not cause change in the state of the local system.
Connect State:
In this state, the control channel FSM is waiting for the QUIC
connection to be completed.
The start events (Events 1, 3-7) are ignored in the Connect state.
In response to a ManualStop event (Event 2), the local system:
* drops the QUIC connection,
* releases all BGP resources,
* sets ConnectRetryCounter to zero,
* stops the ConnectRetryTimer and sets ConnectRetryTimer to zero,
and
* changes its state to Idle.
In response to the ConnectRetryTimer_Expires event (Event 9), the
local system:
* drops the QUIC connection,
* restarts the ConnectRetryTimer,
* stops the DelayOpenTimer and resets the timer to zero,
* initiates a QUIC connection to the other BGP peer,
* continues to listen for a connection that may be initiated by
the remote BGP peer, and
* stays in the Connect state.
If the DelayOpenTimer_Expires event (Event 12) occurs in the
Connect state, the local system:
* sends an OPEN message to its peer,
Retana, et al. Expires 4 September 2024 [Page 32]
Internet-Draft BGP over QUIC Streams March 2024
* sets the HoldTimer to a large value, and
* changes its state to OpenSent.
If the control channel FSM receives a QUICConnection_Valid event
(Event 14), the QUIC connection is processed, and the connection
remains in the Connect state.
If the control channel FSM receives a QUIC_CR_Invalid event (Event
15), the local system rejects the QUIC connection, and the
connection remains in the Connect state.
If the QUIC connection succeeds (Event 16 or Event 17), the local
system checks the DelayOpen attribute prior to processing. If the
DelayOpen attribute is set to TRUE, the local system:
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* sets the DelayOpenTimer to the initial value, and
* stays in the Connect state.
If the DelayOpen attribute is set to FALSE, the local system:
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* completes BGP initialization
* sends an OPEN message to its peer,
* sets the HoldTimer to a large value, and
* changes its state to OpenSent.
A HoldTimer value of 4 minutes is suggested.
If the QUIC connection fails (Event 18), the local system checks
the DelayOpenTimer. If the DelayOpenTimer is running, the local
system:
* restarts the ConnectRetryTimer with the initial value,
* stops the DelayOpenTimer and resets its value to zero,
* continues to listen for a connection that may be initiated by
the remote BGP peer, and
Retana, et al. Expires 4 September 2024 [Page 33]
Internet-Draft BGP over QUIC Streams March 2024
* changes its state to Active.
If the DelayOpenTimer is not running, the local system:
* stops the ConnectRetryTimer to zero,
* drops the QUIC connection,
* releases all BGP resources, and
* changes its state to Idle.
If the QUIC stream fails (Event 30) with StreamID 0, the local
system:
* stops the ConnectRetryTimer to zero,
* drops the QUIC connection,
* releases all BGP resources, and
* changes its state to Idle.
If an OPEN message is received while the DelayOpenTimer is running
(Event 20), the local system:
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* completes the BGP initialization,
* stops and clears the DelayOpenTimer (sets the value to zero),
* sends an OPEN message,
* sends a KEEPALIVE message,
* if the HoldTimer initial value is non-zero,
- starts the KeepaliveTimer with the initial value and
- resets the HoldTimer to the negotiated value,
* else, if the HoldTimer initial value is zero,
- resets the KeepaliveTimer and
- resets the HoldTimer value to zero,
Retana, et al. Expires 4 September 2024 [Page 34]
Internet-Draft BGP over QUIC Streams March 2024
* and changes its state to OpenConfirm.
If the value of the autonomous system field is the same as the
local Autonomous System number, set the connection status to an
internal connection; otherwise it will be "external".
If BGP message header checking (Event 21) or OPEN message checking
detects an error (Event 22), the local system:
* (optionally) If the SendNOTIFICATIONwithoutOPEN attribute is
set to TRUE, then the local system first sends a NOTIFICATION
message with the appropriate error code, and then
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If a NOTIFICATION message is received with a version error (Event
24), the local system checks the DelayOpenTimer. If the
DelayOpenTimer is running, the local system:
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* stops and resets the DelayOpenTimer (sets to zero),
* releases all BGP resources,
* drops the QUIC connection, and
* changes its state to Idle.
If the DelayOpenTimer is not running, the local system:
* stops the ConnectRetryTimer and sets the ConnectRetryTimer to
zero,
* releases all BGP resources,
Retana, et al. Expires 4 September 2024 [Page 35]
Internet-Draft BGP over QUIC Streams March 2024
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* performs peer oscillation damping if the DampPeerOscillations
attribute is set to True, and
* changes its state to Idle.
In response to any other events (Events 8, 10-11, 13, 19, 23,
25-28), the local system:
* if the ConnectRetryTimer is running, stops and resets the
ConnectRetryTimer (sets to zero),
* if the DelayOpenTimer is running, stops and resets the
DelayOpenTimer (sets to zero),
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* performs peer oscillation damping if the DampPeerOscillations
attribute is set to True, and
* changes its state to Idle.
Active State:
In this state, the control channel FSM is trying to acquire a peer
by listening for, and accepting, a QUIC connection.
The start events (Events 1, 3-7) are ignored in the Active state.
In response to a ManualStop event (Event 2), the local system:
* If the DelayOpenTimer is running and the
SendNOTIFICATIONwithoutOPEN session attribute is set, the local
system sends a NOTIFICATION with a Cease,
* releases all BGP resources including stopping the
DelayOpenTimer,
* drops the QUIC connection,
* sets ConnectRetryCounter to zero,
Retana, et al. Expires 4 September 2024 [Page 36]
Internet-Draft BGP over QUIC Streams March 2024
* stops the ConnectRetryTimer and sets the ConnectRetryTimer to
zero, and
* changes its state to Idle.
In response to a ConnectRetryTimer_Expires event (Event 9), the
local system:
* restarts the ConnectRetryTimer (with initial value),
* initiates a QUIC connection to the other BGP peer,
* continues to listen for a QUIC connection that may be initiated
by a remote BGP peer, and
* changes its state to Connect.
If the local system receives a DelayOpenTimer_Expires event (Event
12), the local system:
* sets the ConnectRetryTimer to zero,
* stops and clears the DelayOpenTimer (set to zero),
* completes the BGP initialization,
* sends the OPEN message to its remote peer,
* sets its hold timer to a large value, and
* changes its state to OpenSent.
A HoldTimer value of 4 minutes is also suggested for this state
transition.
If the local system receives a QUICConnection_Valid event (Event
14), the local system processes the QUIC connection flags and
stays in the Active state.
If the local system receives a QUIC_CR_Invalid event (Event 15),
the local system rejects the QUIC connection and stays in the
Active State.
In response to the success of a QUIC connection (Event 16 or Event
17), the local system checks the DelayOpen optional attribute
prior to processing.
If the DelayOpen attribute is set to TRUE, the local system:
Retana, et al. Expires 4 September 2024 [Page 37]
Internet-Draft BGP over QUIC Streams March 2024
- stops the ConnectRetryTimer and sets the ConnectRetryTimer
to zero,
- sets the DelayOpenTimer to the initial value
(DelayOpenTime), and
- stays in the Active state.
If the DelayOpen attribute is set to FALSE, the local system:
- sets the ConnectRetryTimer to zero,
- completes the BGP initialization,
- sends the OPEN message to its peer,
- sets its HoldTimer to a large value, and
- changes its state to OpenSent.
A HoldTimer value of 4 minutes is suggested as a "large value" for
the HoldTimer.
If the local system receives a QUICConnectionFails event (Event
18), the local system:
* restarts the ConnectRetryTimer (with the initial value),
* stops and clears the DelayOpenTimer (sets the value to zero),
* releases all BGP resource,
* increments the ConnectRetryCounter by 1,
* optionally performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If an OPEN message is received and the DelayOpenTimer is running
(Event 20), the local system:
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* stops and clears the DelayOpenTimer (sets to zero),
* completes the BGP initialization,
Retana, et al. Expires 4 September 2024 [Page 38]
Internet-Draft BGP over QUIC Streams March 2024
* sends an OPEN message,
* sends a KEEPALIVE message,
* if the HoldTimer value is non-zero:
- starts the KeepaliveTimer to initial value,
- resets the HoldTimer to the negotiated value,
* else if the HoldTimer is zero:
- resets the KeepaliveTimer (set to zero),
- resets the HoldTimer to zero, and
- changes its state to OpenConfirm.
If the value of the autonomous system field is the same as the
local Autonomous System number, set the connection status to an
internal connection; otherwise it will be external.
If BGP message header checking (Event 21) or OPEN message checking
detects an error (Event 22) (see Section 6), the local system:
* (optionally) sends a NOTIFICATION message with the appropriate
error code if the SendNOTIFICATIONwithoutOPEN attribute is set
to TRUE,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If a NOTIFICATION message is received with a version error (Event
24), the local system checks the DelayOpenTimer. If the
DelayOpenTimer is running, the local system:
* stops the ConnectRetryTimer (if running) and sets the
Retana, et al. Expires 4 September 2024 [Page 39]
Internet-Draft BGP over QUIC Streams March 2024
* ConnectRetryTimer to zero,
* stops and resets the DelayOpenTimer (sets to zero),
* releases all BGP resources,
* drops the QUIC connection, and
* changes its state to Idle.
If the DelayOpenTimer is not running, the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
In response to any other event (Events 8, 10-11, 13, 19, 23,
25-28, 30), the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by one,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
OpenSent State:
In this state, the control channel FSM waits for an OPEN message
from its peer.
The start events (Events 1, 3-7) are ignored in the OpenSent
state.
Retana, et al. Expires 4 September 2024 [Page 40]
Internet-Draft BGP over QUIC Streams March 2024
If a ManualStop event (Event 2) is issued in the OpenSent state,
the local system:
* sends the NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* sets the ConnectRetryCounter to zero, and
* changes its state to Idle.
If an AutomaticStop event (Event 8) is issued in the OpenSent
state, the local system:
* sends the NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all the BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the HoldTimer_Expires (Event 10), the local system:
* sends a NOTIFICATION message with the error code Hold Timer
Expired,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
Retana, et al. Expires 4 September 2024 [Page 41]
Internet-Draft BGP over QUIC Streams March 2024
* changes its state to Idle.
If a QUICConnection_Valid (Event 14), QUIC_CR_Acked (Event 16), or
a QUICConnectionConfirmed event (Event 17) is received, a second
QUIC connection may be in progress. This second QUIC connection
is tracked per Connection Collision processing (Section 6.8 of
[RFC4271]) until an OPEN message is received.
A QUIC Connection Request for an Invalid port (QUIC_CR_Invalid
(Event 15)) is ignored.
If a QUICConnectionFails event (Event 18) is received, the local
system:
* closes the BGP connection,
* restarts the ConnectRetryTimer,
* continues to listen for a connection that may be initiated by
the remote BGP peer, and
* changes its state to Active.
If a QUICStreamClose event (Event 30) with StreamID 0 is received,
the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection, and
* changes its state to Idle.
When an OPEN message is received, all fields are checked for
correctness. If there are no errors in the OPEN message (Event
19), the local system:
* resets the DelayOpenTimer to zero,
* sets the BGP ConnectRetryTimer to zero,
* sends a KEEPALIVE message, and
* sets a KeepaliveTimer,
* sets the HoldTimer according to the negotiated value,
Retana, et al. Expires 4 September 2024 [Page 42]
Internet-Draft BGP over QUIC Streams March 2024
* changes its state to OpenConfirm.
If the negotiated hold time value is zero, then the HoldTimer and
KeepaliveTimer are not started. If the value of the Autonomous
System field is the same as the local Autonomous System number,
then the connection is an "internal" connection; otherwise, it is
an "external" connection.
If the BGP message header checking (Event 21) or OPEN message
checking detects an error (Event 22), the local system:
* sends a NOTIFICATION message with the appropriate error code,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is TRUE, and
* changes its state to Idle.
Collision detection mechanisms need to be applied when a valid BGP
OPEN message is received (Event 19 or Event 20). Please refer to
Section 5.3 in this document and Section 6.8 [RFC4271] of for the
details of the comparison. A CollisionDetectDump event occurs
when the BGP implementation determines, by means outside the scope
of this document, that a connection collision has occurred.
If a connection in the OpenSent state is determined to be the
connection that must be closed, an OpenCollisionDump (Event 23) is
signaled to the state machine. If such an event is received in
the OpenSent state, the local system:
* sends a NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
Retana, et al. Expires 4 September 2024 [Page 43]
Internet-Draft BGP over QUIC Streams March 2024
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If a NOTIFICATION message is received with a version error (Event
24), the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection, and
* changes its state to Idle.
In response to any other event (Events 9, 11-13, 20, 25-28), the
local system:
* sends the NOTIFICATION with the Error Code Finite State Machine
Error,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
OpenConfirm State:
The control channel FSM waits for a KEEPALIVE or NOTIFICATION
message.
Any start event (Events 1, 3-7) is ignored in the OpenConfirm
state.
In response to a ManualStop event (Event 2) initiated by the
operator, the local system:
* sends the NOTIFICATION message with a Cease,
* releases all BGP resources,
Retana, et al. Expires 4 September 2024 [Page 44]
Internet-Draft BGP over QUIC Streams March 2024
* drops the QUIC connection,
* sets the ConnectRetryCounter to zero,
* sets the ConnectRetryTimer to zero, and
* changes its state to Idle.
In response to the AutomaticStop event initiated by the system
(Event 8), the local system:
* sends the NOTIFICATION message with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the HoldTimer_Expires event (Event 10) occurs before a
KEEPALIVE message is received, the local system:
* sends the NOTIFICATION message with the Error Code Hold Timer
Expired,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the local system receives a KeepaliveTimer_Expires event (Event
11), the local system:
Retana, et al. Expires 4 September 2024 [Page 45]
Internet-Draft BGP over QUIC Streams March 2024
* sends a KEEPALIVE message,
* restarts the KeepaliveTimer, and
* remains in the OpenConfirmed state.
In the event of a QUIConnection_Valid event (Event 14), or the
success of a QUIC connection (Event 16 or Event 17) while in
OpenConfirm, the local system needs to track the second
connection.
If a QUIC connection is attempted with an invalid port (Event 15),
the local system will ignore the second connection attempt.
If the local system receives a QUICConnectionFails event (Event
18) from the underlying QUIC or a NOTIFICATION message (Event 25),
the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the local system receives a NOTIFICATION message with a version
error (NotifMsgVerErr (Event 24)), or a QUICStream_Close event
(Event 30) with StreamID 0, the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection, and
* changes its state to Idle.
If the local system receives a valid OPEN message (BGPOpen (Event
19)), the collision detect function is processed per Section 5.3
in this document and Section 6.8 [RFC4271]. If this connection is
to be dropped due to connection collision, the local system:
Retana, et al. Expires 4 September 2024 [Page 46]
Internet-Draft BGP over QUIC Streams March 2024
* sends a NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection (send CONNECTION_CLOSE frame),
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If an OPEN message is received, all fields are checked for
correctness. If the BGP message header checking (BGPHeaderErr
(Event 21)) or OPEN message checking detects an error
(BGPOpenMsgErr (Event 22)), the local system:
* sends a NOTIFICATION message with the appropriate error code,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If, during the processing of another OPEN message, the BGP
implementation determines, by a means outside the scope of this
document, that a connection collision has occurred and this
connection is to be closed, the local system will issue an
OpenCollisionDump event (Event 23). When the local system
receives an OpenCollisionDump event (Event 23), the local system:
* sends a NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
Retana, et al. Expires 4 September 2024 [Page 47]
Internet-Draft BGP over QUIC Streams March 2024
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the local system receives a KEEPALIVE message (KeepAliveMsg
(Event 26)), the local system:
* restarts the HoldTimer and
* changes its state to Established.
In response to any other event (Events 9, 12-13, 20, 27-28), the
local system:
* sends a NOTIFICATION with a code of Finite State Machine Error,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
Established State:
In this state, the control channel FSM can exchange NOTIFICATION,
KEEPALIVE and ROUTEREFRESH messages with its peer. There is no
UPDATE message in the control channel.
Any Start event (Events 1, 3-7) is ignored in the Established
state.
In response to a ManualStop event (initiated by an operator)
(Event 2), the local system:
* sends the NOTIFICATION message with a Cease,
* sets the ConnectRetryTimer to zero,
Retana, et al. Expires 4 September 2024 [Page 48]
Internet-Draft BGP over QUIC Streams March 2024
* deletes all routes associated with this connection,
* releases BGP resources,
* drops the QUIC connection,
* sets the ConnectRetryCounter to zero, and
* changes its state to Idle.
In response to an AutomaticStop event (Event 8), the local system:
* sends a NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* deletes all routes associated with this connection,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
The following text from [RFC4271] is not applicable to BoQ control
channel FSM as there is no UPDATE message in the control channel.
One reason for an AutomaticStop event is: A BGP receives an
UPDATE messages with a number of prefixes for a given peer such
that the total prefixes received exceeds the maximum number of
prefixes configured. The local system automatically
disconnects the peer.
If the HoldTimer_Expires event occurs (Event 10), the local
system:
* sends a NOTIFICATION message with the Error Code Hold Timer
Expired,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
Retana, et al. Expires 4 September 2024 [Page 49]
Internet-Draft BGP over QUIC Streams March 2024
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the KeepaliveTimer_Expires event occurs (Event 11), the local
system:
* sends a KEEPALIVE message, and
* restarts its KeepaliveTimer, unless the negotiated HoldTime
value is zero.
Each time the local system sends a KEEPALIVE message, it restarts
its KeepaliveTimer, unless the negotiated HoldTime value is zero.
A QUICConnection_Valid (Event 14), received for a valid port, will
cause the second connection to be tracked.
An invalid QUIC connection (QUIC_CR_Invalid event (Event 15)) will
be ignored.
In response to an indication that the QUIC connection is
successfully established (Event 16 or Event 17), the second
connection SHALL be tracked until it sends an OPEN message.
If a valid OPEN message (BGPOpen (Event 19)) is received, and if
the CollisionDetectEstablishedState optional attribute is TRUE,
the OPEN message will be checked to see if it collides
(Section 6.8 in [RFC4271]) with any other connection. If the BGP
implementation determines that this connection needs to be
terminated, it will process an OpenCollisionDump event (Event 23).
If this connection needs to be terminated, the local system:
* sends a NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* deletes all routes associated with this connection,
* releases all BGP resources,
* drops the QUIC connection,
Retana, et al. Expires 4 September 2024 [Page 50]
Internet-Draft BGP over QUIC Streams March 2024
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations is set to TRUE, and
* changes its state to Idle.
If the local system receives a NOTIFICATION message (Event 24 or
Event 25) or a QUICConnectionFails (Event 18) from the underlying
QUIC, the local system:
* sets the ConnectRetryTimer to zero,
* deletes all routes associated with this connection,
* releases all the BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* changes its state to Idle.
If the local system receives a QUICStream_Close event (Event 30)
with StreamID 0, the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection, and
* changes its state to Idle.
When a KEEPALIVE message is received, whether it is destined to
the control channel or a function channel, the local system:
* restarts its HoldTimer, if the negotiated HoldTime value is
non-zero, and
* remains in the Established state.
If the local system receives an UPDATE message, it SHOULD be
ignored.
In response to any other event (Events 9, 12-13, 20-22), the local
system:
Retana, et al. Expires 4 September 2024 [Page 51]
Internet-Draft BGP over QUIC Streams March 2024
* sends a NOTIFICATION message with the Error Code Finite State
Machine Error,
* deletes all routes associated with this connection,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources,
* drops the QUIC connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
7.2.2.2. Function Channel Sending FSM
Function channels can only be created after the control channel has
reached Established state. QUIC connection related events (14-18)
MUST be handled by the control channel. However, a function channel
may receive QUIC stream based events (Event 29 and 30).
Function channels are unidirectional. For one AFI/SAFI, there might
be one or two FSMs, one function channel sending FSM and one function
channel receiving FSM.
The following events SHOULD NOT be received in a function channel:
* ManualStart_with_PassiveQUICEstablishment event (Event 4),
* AutomaticStart_with_PassiveQUICEstablishment event (Event 5), or
* AutomaticStart_with_DampPeerOscillations_and_PassiveQUICEstablishm
ent (Event 7).
* QUICConnection_Valid (Event 14)
* QUIC_CR_Invalid (Event 15)
* QUIC_CR_Acked (Event 16)
* QUICConnectionConfirmed (Event 17)
* QUICConnectionFails (Event 18)
Retana, et al. Expires 4 September 2024 [Page 52]
Internet-Draft BGP over QUIC Streams March 2024
Idle State:
Function channel sending FSM starts from idle state as well.
In response to a ManualStart event (Event 1) or an AutomaticStart
event (Event 3), the local system:
* initializes the function channel BGP resources for the peer
connection,
* sets ConnectRetryCounter to zero,
* starts the ConnectRetryTimer with the initial value, and
* changes its state to Connect.
The ManualStop event (Event 2) and AutomaticStop (Event 8) event
are ignored in the Idle state.
If the DampPeerOscillations attribute is set to TRUE, the
following two additional events may occur within the Idle state:
* AutomaticStart_with_DampPeerOscillations (Event 6),
* IdleHoldTimer_Expires (Event 13).
Upon receiving these 2 events, the local system will use these
events to prevent peer oscillations. The method of preventing
persistent peer oscillation is outside the scope of this document.
Any other event (Event 9-12, 19-30) received in the Idle state
does not cause change in the state of the local system.
Connect State:
The start events (Events 1, 3-7) are ignored in the Connect state.
In response to a ManualStop event (Event 2), the local system:
* releases all BGP resources for the channel,
* sets ConnectRetryCounter to zero,
* stops the ConnectRetryTimer and sets ConnectRetryTimer to zero,
and
* changes its state to Idle.
In response to the ConnectRetryTimer_Expires event (Event 9), the
local system:
Retana, et al. Expires 4 September 2024 [Page 53]
Internet-Draft BGP over QUIC Streams March 2024
* restarts the ConnectRetryTimer, and
* changes its state to Idle.
The local system:
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* sends an OPEN message to its peer using a unidirectional QUIC
stream,
* sets the HoldTimer to a large value,
* record the StreamID, and
* changes its state to OpenSent.
If a QUICStreamClose event (Event 30) is received and the StreamID
matches the function channel's StreamID, the local system:
* releases all BGP resources for the channel,
* sets ConnectRetryCounter to zero,
* stops the ConnectRetryTimer and sets ConnectRetryTimer to zero,
and
* changes its state to Idle.
If the value of the autonomous system field is the same as the
local Autonomous System number, set the connection status to an
internal connection; otherwise it will be "external".
If a NOTIFICATION message is received with a version error (Event
24) in the control channel destined to the function channel, the
local system:
* stops the ConnectRetryTimer (if running) and sets the
ConnectRetryTimer to zero,
* release all BGP resources for the function channel,
* terminates the function channel/QUIC stream,
* performs peer oscillation damping if the DampPeerOscillations
attribute is set to True, and
Retana, et al. Expires 4 September 2024 [Page 54]
Internet-Draft BGP over QUIC Streams March 2024
* changes its state to Idle.
OpenSent State:
A BoQ speaker waits for an OPEN message from its peer in the
control channel with destination StreamID matches its own
StreamID.
The start events (Events 1, 3, 5 and 7) are ignored in the
OpenSent state.
If a ManualStop event (Event 2) is issued in the OpenSent state,
the local system:
* sends the NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources for this channel,
* closes the stream,
* sets the ConnectRetryCounter to zero, and
* changes its state to Idle.
If an AutomaticStop event (Event 8) is issued in the OpenSent
state, the local system:
* sends the NOTIFICATION with a Cease,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources for this channel,
* closes the stream,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the HoldTimer_Expires event (Event 10) or QUICStreamClose event
(Event 30) is received in the OpenSent state, the local system:
* sends the NOTIFICATION with a Cease,
Retana, et al. Expires 4 September 2024 [Page 55]
Internet-Draft BGP over QUIC Streams March 2024
* sets the ConnectRetryTimer to zero,
* releases all BGP resources for this channel,
* closes the stream,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
When an OPEN message from its peer is received, it's checked for
correctness. In case of error, the local BoQ speaker:
* sends a NOTFICATION message,
* closes the channel/QUIC stream,
* releases the corresponding BGP resources for the channel,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is TRUE, and
* and changes its state to Idle.
When an OPEN message is received and there is no error in the
received OPEN message, the local system:
* sends a KEEPALIVE message,
* sets a KeepAlive timer,
* sets the HoldTimer, and
* changes its state to OpenConfirm.
If a NOTIFICATION message is received in the control channel with
version error (Event 24) and matching StreamID, the local system:
* resale the related BGP resources,
* drop the stream, and
* changes its state to Idle.
Retana, et al. Expires 4 September 2024 [Page 56]
Internet-Draft BGP over QUIC Streams March 2024
In response to any other event (Events 11, 13, 25-28), the local
system:
* sends the NOTIFICATION with the Error Code Finite State Machine
Error,
* releases related BGP resources,
* drops the QUIC stream connection/channel,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
OpenConfirm State:
In this state, BoQ waits for a KEEPALIVE or NOTIFICATION message.
Any start event (Events 1, 3-7) is ignored in the OpenConfirm
state.
In response to a ManualStop event (Event 2) initiated by the
operator, the local system:
* sends the NOTIFICATION message with a Cease,
* releases all BGP resources for the channel,
* closes the stream,
* sets the ConnectRetryCounter to zero,
* sets the ConnectRetryTimer to zero, and
* changes its state to Idle.
In response to the AutomaticStop event initiated by the system
(Event 8), the local system:
* sends the NOTIFICATION message with a Cease,
* releases all BGP resources,
* drops the stream/channel connection,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
Retana, et al. Expires 4 September 2024 [Page 57]
Internet-Draft BGP over QUIC Streams March 2024
* changes its state to Idle.
If the HoldTimer_Expires event (Event 10) occurs before a
KEEPALIVE message is received, the local system:
* sends the NOTIFICATION message with the Error Code Hold Timer
Expired,
* releases related BGP resources,
* drops the stream/channel connection,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the local system receives a KeepaliveTimer_Expires event (Event
11), the local system:
* sends a KEEPALIVE message,
* restarts the KeepaliveTimer, and
* remains in the OpenConfirmed state.
If the local system receives a QUICStreamClose event (Event 30) or
a NOTIFICATION message (Event 25), the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources for the channel,
* closes the channel connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the local system receives a NOTIFICATION message with a version
error (NotifMsgVerErr (Event 24)), the local system:
* sets the ConnectRetryTimer to zero,
* releases all BGP resources for the channel,
Retana, et al. Expires 4 September 2024 [Page 58]
Internet-Draft BGP over QUIC Streams March 2024
* drops the stream connection, and
* changes its state to Idle.
If an OPEN message is received in the control channel for this
function channel, all fields are checked for correctness. If the
BGP message header checking (BGPHeaderErr (Event 21)) or OPEN
message checking detects an error (BGPOpenMsgErr (Event 22)), the
local system:
* sends a NOTIFICATION message with the appropriate error code,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources for the channel,
* drops the stream connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the local system receives a KEEPALIVE message (KeepAliveMsg
(Event 26)) from the control channel with matching stream ID, the
local system:
* restarts the HoldTimer and
* changes its state to Established.
In response to any other event (Events 9, 12-13, 20, 27-28), the
local system:
* sends a NOTIFICATION with a code of Finite State Machine Error,
* sets the ConnectRetryTimer to zero,
* releases all BGP resources for the channel,
* drops the stream connection,
* increments the ConnectRetryCounter by 1,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
Retana, et al. Expires 4 September 2024 [Page 59]
Internet-Draft BGP over QUIC Streams March 2024
* changes its state to Idle.
Established State:
When the sending function channel reaches established state, it
sends UPDATE, NOTIFCATION and KEEPALIVE messages to its peer.
Any Start event (Events 1, 3, 6) is ignored in the Established
state.
In response to a ManualStop event (initiated by an operator)(Event
2), the local system:
* sends the NOTIFICATION message with a Cease,
* deletes all routes associated with this connection,
* releases related BGP resources for the channel,
* drops the stream/channel connection,
* changes its state to Idle.
In response to an AutomaticStop event (Event 8), the local system:
* sends a NOTIFICATION with a Cease,
* deletes all routes associated with this connection,
* releases related BGP resources,
* drops the stream/channel connection,
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the HoldTimer_Expires event occurs (Event 10), the local
system:
* sends a NOTIFICATION message with the Error Code Hold Timer
Expired,
* releases related BGP resources,
* drops the stream/channel connection,
Retana, et al. Expires 4 September 2024 [Page 60]
Internet-Draft BGP over QUIC Streams March 2024
* (optionally) performs peer oscillation damping if the
DampPeerOscillations attribute is set to TRUE, and
* changes its state to Idle.
If the KeepaliveTimer_Expires event occurs (Event 11), the local
system:
* sends a KEEPALIVE message, and
* restarts its KeepaliveTimer, unless the negotiated HoldTime
value is zero.
Any QUIC event (Event 14-17) received SHOULD be ignored.
If the local system receives a NOTIFICATION message (Event 24 or
25) from the control channel with matching StreamID or a
QUICStreamClose event (Event 30), the local system:
* deletes all routes associated with this AFI/SAFI,
* releases the related BGP resources for this channel,
* drops the stream/channel connection,
* changes its state to Idle.
If the local system receives a KEEPALIVE message (Event 26) in the
control channel with matching StreamID, the local system:
* restarts its HoldTimer, if the negotiated HoldTime value is
non-zero, and
* remains in the Established state.
A function channel is unidirectional, it SHOULD NOT receive any
UPDATE message from the control channel with matching StreamID.
In case an UPDATE message is received, it SHOULD be ignored.
7.2.2.3. Function Channel Receiving FSM
In BoQ, function channels are unidirectional, hence after the control
channel reaches established state, as the receiving side a BoQ
speaker doesn't know what function channels will be created by its
peer. A BoQ implementation is suggested to have a central process or
thread to handle BGP packets received from its peer in function
channels that don't have receiving FSMs yet, we can call this the
packet dispatcher.
Retana, et al. Expires 4 September 2024 [Page 61]
Internet-Draft BGP over QUIC Streams March 2024
This dispatcher SHOULD only handle OPEN messages received from its
BoQ peer, any other BGP messages SHOULD be ignored. When an OPEN
message is received by the dispatcher, and there is no receiving FSM
created for the function channel, a function Chanel receiving FSM
SHOULD be created to handle packets from the stream. For example,
when an OPEN packet for IPv6 unicast is received on stream #2, and no
receiving FSM for IPv6 unicast exists, a receiving FSM SHOULD be
created for IPv6 unicast, and the StreamID should be set to 2. Ifa
receiving FSM for IPv6 unicast with different StreamID already
exists, a NOTIFICATION with BoQ error code, BoQ channel conflict
subcode SHOULD be sent in the control channel (see Section 5.3).
There is no "Active State" or "OpenSent State" in a function channel
receiving FSM.
Idle State:
After a function channel receiving FSM is created, it starts from
the Idle state.
In this state, the local system:
* initialize related BGP resources for the peer connection for
the AFI/SAFI,
* records the StreamID, and
* changes its state to Connect.
The ManualStop event (Event 2) and AutomaticStop (Event 8) event
are ignored in the Idle state.
Connect State:
In this state, the function channel receiving FSM process the
received OPEN message, if there is no error in the OPEN message,
the local system:
* sends an OPEN message in the control channel as acknowledgement
with the StreamID,
* sends a KEEPALIVE message in the control channel,
* if the HoldTimer initial value is non-zero,
- starts the KeepaliveTimer with the initial value and
- resets the HoldTimer to the negotiated value,
* else, if the HoldTimer initial value is zero,
Retana, et al. Expires 4 September 2024 [Page 62]
Internet-Draft BGP over QUIC Streams March 2024
- resets the KeepaliveTimer and
- resets the HoldTimer value to zero,
* and changes its state to OpenConfirm.
If BGP message header checking (Event 21) or OPEN message checking
detects an error (Event 22), the local system:
* (optionally) If the SendNOTIFICATIONwithoutOPEN attribute is
set to TRUE, then the local system first sends a NOTIFICATION
message with the appropriate error code, and then
* releases all related BGP resources,
* delete the function channel receiving FSM.
If a NOTIFICATION message is received with a version error (Event
24), or a QUICStreamCLose event (Event 30) is received, the local
system:
* releases all related BGP resources for the channel,
* delete the function channel receiving FSM.
In response to any other events (Events 8, 10-11, 13, 19, 23,
25-28), the local system:
* releases all related BGP resources,
* delete the function channel receiving FSM.
OpenConfirm State:
In the state, the receiving FSM wait for a KEEPALIVE or
NOTIFICATION message.
Any start event (Events 1, 3-7) is ignored in the OpenConfirm
state.
In response to a ManualStop event (Event 2) initiated by the
operator or the AutomaticStop event initiated by the system (Event
8), the local system:
* sends the NOTIFICATION message with a Cease in the control
channel,
* releases all related BGP resources,
Retana, et al. Expires 4 September 2024 [Page 63]
Internet-Draft BGP over QUIC Streams March 2024
* delete the function channel receiving FSM.
If the HoldTimer_Expires event (Event 10) occurs before a
KEEPALIVE message is received, the local system:
* sends the NOTIFICATION message with the Error Code Hold Timer
Expired,
* releases all related BGP resources,
* delete the function channel receiving FSM.
If the local system receives a KeepaliveTimer_Expires event (Event
11), the local system:
* sends a KEEPALIVE message in the control channel,
* restarts the KeepaliveTimer, and
* remains in the OpenConfirmed state.
If the local system receives a NOTIFICATION message with a version
error (NotifMsgVerErr (Event 24)), or a QUICStreamCLose event
(Event 30) is received, the local system:
* restarts the KeepaliveTimer, and
* remains in the OpenConfirmed state.
If a valid OPEN message is received on the same stream, it SHOULD
be ignored.
If an OPEN message is received with error, (BGPHeaderErr (Event
21)or BGPOpenMsgErr (Event 22)), the local system:
* sends a NOTIFICATION message with the appropriate error code in
the control channel,
* releases all related BGP resources,
* delete the function channel receiving FSM.
If the local system receives a KEEPALIVE message (KeepAliveMsg
(Event 26)), the local system:
* restarts the HoldTimer and
* changes its state to Established.
Retana, et al. Expires 4 September 2024 [Page 64]
Internet-Draft BGP over QUIC Streams March 2024
In response to any other event (Events 9, 12-13, 20, 27-28), the
local system:
* sends a NOTIFICATION with a code of Finite State Machine Error,
* releases all related BGP resources,
* delete the function channel receiving FSM.
Established State:
In the Established state, a function channel receiving FSM can
receive UPDATE, NOTIFICATION, and KEEPALIVE messages from its
peer.
Any Start event (Events 1, 3-7) is ignored in the Established
state.
In response to a ManualStop event (initiated by an operator)
(Event 2), or an AutomaticStop event (Event 8), the local system:
* sends the NOTIFICATION message with a Cease in the control
channel,
* deletes all routes associated with this connection,
* releases all related BGP resources,
* delete the function channel receiving FSM.
If the HoldTimer_Expires event occurs (Event 10), the local
system:
* sends a NOTIFICATION message with the Error Code Hold Timer
Expired in the control channel,
* releases all related BGP resources,
* delete the function channel receiving FSM.
If the KeepaliveTimer_Expires event occurs (Event 11), the local
system:
* sends a KEEPALIVE message in the control channel, and
* restarts its KeepaliveTimer, unless the negotiated HoldTime
value is zero.
Retana, et al. Expires 4 September 2024 [Page 65]
Internet-Draft BGP over QUIC Streams March 2024
Each time the local system sends a KEEPALIVE in the control
channel, it restarts its KeepaliveTimer, unless the negotiated
HoldTime value is zero.
If the local system receives a NOTIFICATION message (Event 24 or
Event 25), or a QUICStreamCLose event (Event 30) is received, the
local system:
* deletes all routes associated with this connection,
* releases all related BGP resources,
* delete the function channel receiving FSM.
If the local system receives a KEEPALIVE message (Event 26), the
local system:
* restarts its HoldTimer, if the negotiated HoldTime value is
non-zero, and
* remains in the Established state.
If the local system receives an UPDATE message (Event 27), the
local system:
* processes the message,
* restarts its HoldTimer, if the negotiated HoldTime value is
non-zero, and
* remains in the Established state.
If an UPDATE message is received with error (Event 28), the local
system:
* sends a NOTIFICATION message with an Update error,
* deletes all routes associated with this connection,
* releases all related BGP resources,
* delete the function channel receiving FSM.
In response to any other event (Events 9, 12-13, 20-22), the local
system:
* sends a NOTIFICATION message with the Error Code Finite State
Machine Error,
Retana, et al. Expires 4 September 2024 [Page 66]
Internet-Draft BGP over QUIC Streams March 2024
* deletes all routes associated with this connection,
* releases all related BGP resources,
* delete the function channel receiving FSM.
8. Operational Considerations
8.1. Using Multi-Channel BGP over QUIC
The decision to use BoQ instead of the TCP-based mechanism defined in
[RFC4271] is an operational decision and out of the scope of this
document. An implementation MUST provide a configuration mechanism
to enable BoQ on a per-peer basis.
Connectivity problems (e.g., blocking UDP) can result in a failure to
establish a QUIC connection; BGP speakers SHOULD attempt to establish
a TCP-based BGP session in this case.
8.2. BGP Multi-Channel Prioritization
One of the drawbacks of a single BGP session is that control plane
messages for all supported Network Layer protocols use the same
connection, which may cause resource contention.
QUIC [RFC9000] does not provide a mechanism for exchanging
prioritization information. Instead, it recommends that
implementations provide ways for an application to indicate the
relative priority of streams, in this case, mapped to BGP channels.
An operator should prioritize BGP channels (streams) that carry
critical control plane information if the functionality is available.
The definition of this functionality and the determination of the
importance of a BGP session are both outside the scope of this
document.
9. Security Considerations
This document replaces the transport protocol layer of BGP from TCP
to QUIC. It does not modify the basic protocol specifications of
BGP, and therefore does not introduce new security risks to the basic
BGP protocol. The non-TCP-related considerations of [RFC4271],
[RFC4272], and [RFC7454] apply to the specification in this document.
BoQ enhances transport-layer security for BGP sessions, refer to
[RFC7454]:
(1) Supports QUIC server identity authentication.
Retana, et al. Expires 4 September 2024 [Page 67]
Internet-Draft BGP over QUIC Streams March 2024
(2) (Optional) Supports QUIC client identity authentication.
(3) Confidentiality protection of BGP messages is supported. All
BGP messages are encrypted for transmission.
(4) Supports integrity protection for BGP messages.
The use of a specific UDP port number and an ALPN token protects a
BoQ speaker from attempts to establish an unexpected BGP session.
Additionally, all packets directed to UDP port TBD on the local
device and sourced from an address not known or permitted to become a
BGP neighbor SHOULD be discarded.
With BGP multi-channel support using QUIC streams, it separates the
control plane traffic over multiple channels. The effect of a
session-based vulnerability is reduced; only a single channel is
affected and not the whole connection. The result is increased
resiliency.
On the other hand, a high number of BGP channels may result in higher
resource utilization and the risk of depletion. Also, more channels
may imply additional configuration and operational complexity.
10. IANA Considerations
10.1. UDP Port for BoQ
IANA is requested to assign a UDP port (TBD1) from the "Service Name
and Transport Protocol Port Number Registry" as follows:
Retana, et al. Expires 4 September 2024 [Page 68]
Internet-Draft BGP over QUIC Streams March 2024
+---------------------------+---------------+
| Service Name | boq |
+---------------------------+---------------+
| Port Number | TBD1 |
+---------------------------+---------------+
| Transport Protocol | udp |
+---------------------------+---------------+
| Description | BGP over QUIC |
+---------------------------+---------------+
| Assignee | IETF |
+---------------------------+---------------+
| Contact | IDR WG |
+---------------------------+---------------+
| Registration Data | TBD |
+---------------------------+---------------+
| Reference | this document |
+---------------------------+---------------+
| Unauthorized Use Reported | idr@ietf.org |
+---------------------------+---------------+
Table 5: Port Number Registry
10.2. Registration of the BGP4 Identification String
This document creates a new registration for the identification of
BGP [RFC4271] in the "TLS Application-Layer Protocol Negotiation
(ALPN) Protocol IDs" registry.
The "boq" string identifies BGP-4 [RFC4271] over QUIC:
Protocol: Multi-Channel BGP over QUIC
Identification Sequence: 0x62 0x6f 0x71 ("boq")
Specification: This document
10.3. BGP Over QUIC Capability
IANA is asked to assign a new Capability code [RFC5492] for the BGP
over QUIC Capability Section 5.1 as follows:
Retana, et al. Expires 4 September 2024 [Page 69]
Internet-Draft BGP over QUIC Streams March 2024
+-------------------+-----------------+
| Value | TBD2 |
+-------------------+-----------------+
| Description | BoQ Capability |
+-------------------+-----------------+
| Reference | [This Document] |
+-------------------+-----------------+
| Change Controller | IETF |
+-------------------+-----------------+
Table 6: BoQ Capability Registration
10.4. Error Code
This document defines a new NOTIFICATION error code and related
subcodes related to the BoQ procedures. IANA is asked to assign a
new error code from the "BGP Error (Notification) Codes" registry
with the name "BGP over QUIC Message Error", referencing this
document.
IANA is asked to create a new registry for the error subcodes as
follows:
Under "Border Gateway Protocol (BGP) Parameters",
under "BGP Error Subcodes":
Registry: "BGP over QUIC Message Error subcodes"
Reference: this document
Registration Procedure(s): Values 0-127 Standards Action,
values 128-255 First Come First Served
+=======+=========================+=================+
| Value | Name | Reference |
+=======+=========================+=================+
| 0 | Reserved | [this document] |
+-------+-------------------------+-----------------+
| 1 | BoQ Capability Mismatch | [this document] |
+-------+-------------------------+-----------------+
| 2 | BoQ Connection Reset | [this document] |
+-------+-------------------------+-----------------+
| 3 | BoQ Channel Reset | [this document] |
+-------+-------------------------+-----------------+
| 4 | BoQ Channel Conflict | [this document] |
+-------+-------------------------+-----------------+
| 5-255 | Unassigned | |
+-------+-------------------------+-----------------+
Table 7: BGP over QUIC Message Error subcodes
Retana, et al. Expires 4 September 2024 [Page 70]
Internet-Draft BGP over QUIC Streams March 2024
11. Acknowledgement
This document references the text and procedures defined in
[I-D.ietf-idr-bgp-multisession], and we are grateful for their
contributions.
The authors would like to thank xx for review and comments.
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<https://www.rfc-editor.org/info/rfc4271>.
[RFC4486] Chen, E. and V. Gillet, "Subcodes for BGP Cease
Notification Message", RFC 4486, DOI 10.17487/RFC4486,
April 2006, <https://www.rfc-editor.org/info/rfc4486>.
[RFC5492] Scudder, J. and R. Chandra, "Capabilities Advertisement
with BGP-4", RFC 5492, DOI 10.17487/RFC5492, February
2009, <https://www.rfc-editor.org/info/rfc5492>.
[RFC6286] Chen, E. and J. Yuan, "Autonomous-System-Wide Unique BGP
Identifier for BGP-4", RFC 6286, DOI 10.17487/RFC6286,
June 2011, <https://www.rfc-editor.org/info/rfc6286>.
[RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,
"Transport Layer Security (TLS) Application-Layer Protocol
Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
July 2014, <https://www.rfc-editor.org/info/rfc7301>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed and Secure Transport", RFC 9000,
DOI 10.17487/RFC9000, May 2021,
<https://www.rfc-editor.org/info/rfc9000>.
Retana, et al. Expires 4 September 2024 [Page 71]
Internet-Draft BGP over QUIC Streams March 2024
12.2. Informative References
[I-D.ietf-idr-bgp-multisession]
Scudder, J., Appanna, C., and I. Varlashkin, "Multisession
BGP", Work in Progress, Internet-Draft, draft-ietf-idr-
bgp-multisession-07, 13 September 2012,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-bgp-
multisession-07>.
[I-D.ietf-idr-rfc7752bis]
Talaulikar, K., "Distribution of Link-State and Traffic
Engineering Information Using BGP", Work in Progress,
Internet-Draft, draft-ietf-idr-rfc7752bis-17, 25 August
2023, <https://datatracker.ietf.org/doc/html/draft-ietf-
idr-rfc7752bis-17>.
[RFC2918] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918,
DOI 10.17487/RFC2918, September 2000,
<https://www.rfc-editor.org/info/rfc2918>.
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006,
<https://www.rfc-editor.org/info/rfc4272>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<https://www.rfc-editor.org/info/rfc4760>.
[RFC7313] Patel, K., Chen, E., and B. Venkatachalapathy, "Enhanced
Route Refresh Capability for BGP-4", RFC 7313,
DOI 10.17487/RFC7313, July 2014,
<https://www.rfc-editor.org/info/rfc7313>.
[RFC7454] Durand, J., Pepelnjak, I., and G. Doering, "BGP Operations
and Security", BCP 194, RFC 7454, DOI 10.17487/RFC7454,
February 2015, <https://www.rfc-editor.org/info/rfc7454>.
[RFC9234] Azimov, A., Bogomazov, E., Bush, R., Patel, K., and K.
Sriram, "Route Leak Prevention and Detection Using Roles
in UPDATE and OPEN Messages", RFC 9234,
DOI 10.17487/RFC9234, May 2022,
<https://www.rfc-editor.org/info/rfc9234>.
Authors' Addresses
Retana, et al. Expires 4 September 2024 [Page 72]
Internet-Draft BGP over QUIC Streams March 2024
Alvaro Retana
Futurewei Technologies
2330 Central Expressway
Santa Clara, CA 95050
United States of America
Email: aretana@futurewei.com
Yingzhen Qu
Futurewei Technologies
2330 Central Expressway
Santa Clara, CA 95050
United States of America
Email: yingzhen.qu@futurewei.com
Jeffrey Haas
Juniper Networks
1133 Innovation Way
Sunnyvale, CA 94089
United States of America
Email: jhaas@juniper.net
Shuanglong Chen
Huawei Technologies
No.156 Beiqing Rd.
Beijing
100095
China
Email: chenshuanglong@huawei.com
Jeff Tantsura
Nvidia
United States of America
Email: jefftant.ietf@gmail.com
Retana, et al. Expires 4 September 2024 [Page 73]