IPPM Working Group R. Gandhi, Ed.
Internet-Draft C. Filsfils
Intended status: Standards Track Cisco Systems, Inc.
Expires: 6 August 2022 D. Voyer
Bell Canada
M. Chen
Huawei
B. Janssens
Colt
R. Foote
Nokia
2 February 2022
Simple TWAMP (STAMP) Extensions for Segment Routing Networks
draft-ietf-ippm-stamp-srpm-03
Abstract
Segment Routing (SR) leverages the source routing paradigm. SR is
applicable to both Multiprotocol Label Switching (SR-MPLS) and IPv6
(SRv6) forwarding planes. This document specifies RFC 8762 (Simple
Two-Way Active Measurement Protocol (STAMP)) extensions for SR
networks, for both SR-MPLS and SRv6 forwarding planes by augmenting
the optional extensions defined in RFC 8972.
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 6 August 2022.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3
2.3. Reference Topology . . . . . . . . . . . . . . . . . . . 4
3. Destination Node Address TLV . . . . . . . . . . . . . . . . 4
4. Return Path TLV . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Return Path Sub-TLVs . . . . . . . . . . . . . . . . . . 7
4.1.1. Return Path Control Code Sub-TLV . . . . . . . . . . 7
4.1.2. Return Address Sub-TLV . . . . . . . . . . . . . . . 8
4.1.3. Return Segment List Sub-TLVs . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . . . . . . . . . . 14
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
Segment Routing (SR) leverages the source routing paradigm for
Software Defined Networks (SDNs). SR is applicable to both
Multiprotocol Label Switching (SR-MPLS) and IPv6 (SRv6) forwarding
planes [RFC8402]. SR Policies as defined in
[I-D.ietf-spring-segment-routing-policy] are used to steer traffic
through a specific, user-defined paths using a stack of Segments. A
comprehensive SR Performance Measurement (PM) toolset is one of the
essential requirements to measure network performance to provide
Service Level Agreements (SLAs).
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The Simple Two-Way Active Measurement Protocol (STAMP) provides
capabilities for the measurement of various performance metrics in IP
networks [RFC8762] without the use of a control channel to pre-signal
session parameters. [RFC8972] defines optional extensions, in the
form of TLVs, for STAMP. Note that the YANG data model defined in
[I-D.ietf-ippm-stamp-yang] can be used to provision the STAMP
Session-Sender and STAMP Session-Reflector.
The STAMP test packets are transmitted along an IP path between a
Session-Sender and a Session-Reflector to measure performance delay
and packet loss along that IP path. It may be desired in SR networks
that the same path (same set of links and nodes) between the Session-
Sender and Session-Reflector is used for the STAMP test packets in
both directions. This is achieved by using the STAMP [RFC8762]
extensions for SR-MPLS and SRv6 networks specified in this document
by augmenting the optional extensions defined in [RFC8972].
2. Conventions Used in This Document
2.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119] [RFC8174]
when, and only when, they appear in all capitals, as shown here.
2.2. Abbreviations
MPLS: Multiprotocol Label Switching.
PM: Performance Measurement.
SID: Segment ID.
SL: Segment List.
SR: Segment Routing.
SR-MPLS: Segment Routing with MPLS forwarding plane.
SRv6: Segment Routing with IPv6 forwarding plane.
SSID: STAMP Session Identifier.
STAMP: Simple Two-Way Active Measurement Protocol.
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2.3. Reference Topology
In the reference topology shown below, the STAMP Session-Sender S1
initiates a STAMP test packet and the STAMP Session-Reflector R1
transmits a reply STAMP test packet. The reply test packet may be
transmitted to the Session-Sender S1 on the same path (same set of
links and nodes) or a different path in the reverse direction from
the path taken towards the Session-Reflector R1.
The nodes S1 and R1 may be connected via a link or an SR path
[RFC8402]. The link may be a physical interface, virtual link, or
Link Aggregation Group (LAG) [IEEE802.1AX], or LAG member link. The
SR path may be an SR Policy [I-D.ietf-spring-segment-routing-policy]
on node S1 (called head-end) with destination to node R1 (called
tail-end).
T1 T2
/ \
+-------+ Test Packet +-------+
| | - - - - - - - - - ->| |
| S1 |=====================| R1 |
| |<- - - - - - - - - - | |
+-------+ Reply Test Packet +-------+
\ /
T4 T3
STAMP Session-Sender STAMP Session-Reflector
Reference Topology
3. Destination Node Address TLV
The Session-Sender may need to transmit test packets to the Session-
Reflector with a different destination address not matching an
address on the Session-Reflector e.g. when the STAMP test packet is
encapsulated by a tunneling protocol or an MPLS Segment List with
IPv4 address from 127/8 range or Segment Routing Header (SRH) with
IPv6 address ::1/128. For testing ECMPs, the Session-Sender may
select different IPv4 addresses from 127/8 range or select different
Flow Label values for IPv6. When using IPv4 destination address from
127/8 range, the STAMP test packet may not reach the intended
Session-Reflector in an error condition, an un-intended node may
transmit reply test packets resulting in reporting of invalid
measurement metrics.
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[RFC8972] defines STAMP test packets that can include one or more
optional TLVs. In this document, Destination Node Address TLV (Type
TBA1) is defined for STAMP test packet [RFC8972] and has the
following format shown in Figure 1:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type=TBA1 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. Address .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Destination Node Address TLV Format
The Length field is used to decide the Address Family of the Address.
The STAMP TLV Flags are set using the procedures described in
[RFC8972].
The Destination Node Address TLV is optional. The Destination Node
Address TLV indicates the address of the intended Session-Reflector
node of the test packet. When Session-Sender test packet destination
address is different than the actual Session-Reflector address, the
actual Session-Reflector address SHOULD be transmitted to the
Session-Reflector by including a Destination Node Address TLV.
D (Wrong Destination Flag): A one-bit flag at position TBA3.
D (Wrong Destination with Reply Required): A Session-Sender MUST set
the D flag to 0 before transmitting an extended STAMP test packet
when test packet reply is required. A Session-Reflector that
supports this TLV, MUST set the D flag to 1 if the Session-Reflector
determined that it is not the intended Destination as identified in
the Destination Node Address TLV. Otherwise, the Session-Reflector
MUST set the D flag in the reply test packet to 0.
D (Wrong Destination with No Reply Required): A Session-Sender MUST
set the D flag to 1 before transmitting an extended STAMP test packet
when test packet reply is not required. A Session-Reflector that
supports this TLV, MUST NOT reply and MUST drop the packet if the
Session-Reflector determined that it is not the intended Destination
as identified in the Destination Node Address TLV.
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4. Return Path TLV
For end-to-end SR paths, the Session-Reflector may need to transmit
the reply test packet on a specific return path. The Session-Sender
can request this in the test packet to the Session-Reflector using a
Return Path TLV. With this TLV carried in the Session-Sender test
packet, signaling and maintaining dynamic SR network state for the
STAMP sessions on the Session-Reflector are avoided.
For links, the Session-Reflector may need to transmit the reply test
packet on the same incoming link in the reverse direction. The
Session-Sender can request this in the test packet to the Session-
Reflector using a Return Path TLV.
[RFC8972] defines STAMP test packets that can include one or more
optional TLVs. In this document, the TLV Type (value TBA2) is
defined for the Return Path TLV that carries the return path for the
Session-Sender test packet. The format of the Return Path TLV is
shown in Figure 2:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type=TBA2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Return Path Sub-TLVs |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Return Path TLV
The STAMP TLV Flags are set using the procedures described in
[RFC8972].
The Return Path TLV is optional. The Session-Sender MUST only insert
one Return Path TLV in the STAMP test packet. The Session-Reflector
that supports this TLV, MUST only process the first Return Path TLV
in the test packet and ignore other Return Path TLVs if present, and
it MUST NOT add Return Path TLV in the reply test packet. The
Session-Reflector that supports this TLV MUST reply using the Return
Path received in the Session-Sender test packet. Otherwise, the
procedure defined in [RFC8762] is followed by the Session-Reflector.
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4.1. Return Path Sub-TLVs
The Return Path TLV contains one or more Sub-TLVs to carry the
information for the requested return path. A Return Path Sub-TLV can
carry Return Path Control Code, Return Path IP Address or Return Path
Segment List.
The STAMP Sub-TLV Flags are set using the procedures described in
[RFC8972].
When Return Path Sub-TLV is present in the Session-Sender test
packet, the Session-Reflector that supports this TLV, MUST transmit
reply test packet using the return path information specified in the
Return Path Sub-TLV.
A Return Path TLV MUST NOT contain both Control Code Sub-TLV as well
as Return Address or Return Segment List Sub-TLV.
4.1.1. Return Path Control Code Sub-TLV
The format of the Return Path Control Code Sub-TLV is shown in
Figure 3. The Type of the Return Path Control Code Sub-TLV is
defined as following:
* Type (value 1): Return Path Control Code. The Session-Sender can
request the Session-Reflector to transmit the reply test packet
based on the flags defined in the Control Code field.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type=1 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Control Code Sub-TLV in Return Path TLV
Control Code Flags (32-bit): Defined as follows.
0x0: No Reply Requested.
0x1: Reply Requested on the Same Link.
When Control Code flag is set to 0x0 in the Session-Sender test
packet, the Session-Reflector does not transmit reply test packet to
the Session-Sender and terminates the STAMP test packet. Only the
one-way measurement is applicable in this case. Optionally, the
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Session-Reflector may locally stream performance metrics via
telemetry using the information from the received test packet. All
other Return Path Sub-TLVs MUST be ignored in this case.
When Control Code flag is set to 0x1 in the Session-Sender test
packet, the Session-Reflector transmits the reply test packet over
the same incoming link where the test packet is received in the
reverse direction towards the Session-Sender. All other Return Path
Sub-TLVs MUST be ignored in this case.
4.1.2. Return Address Sub-TLV
The STAMP reply test packet may be transmitted to the Session-Sender
to a different destination address on the Session-Sender using Return
Path TLV. For this, the Session-Sender can specify in the test
packet the receiving destination node address for the Session-
Reflector reply test packet. When transmitting the STAMP test packet
to a different destination address, the Session-Sender MUST follow
the procedure defined in Section 4.3 of [RFC8762].
The format of the Return Address Sub-TLV is shown in Figure 4. The
Address Family field indicates the type of the address, and it SHALL
be set to one of the assigned values in the "IANA Address Family
Numbers" registry. The Type of the Return Address Sub-TLV is defined
as following:
* Type (value 2): Return Address. Destination node address of the
Session-Reflector reply test packet different than the Source
Address in the Session-Sender test packet.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type=2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Address Family |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. Address .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Return Address Sub-TLV in Return Path TLV
4.1.3. Return Segment List Sub-TLVs
The format of the Segment List Sub-TLVs in the Return Path TLV is
shown in Figures 5, 6, and 7. The segment entries MUST be in network
order. The Segment List Sub-TLV can be one of the following Types:
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* Type (value 3): SR-MPLS Label Stack of the Return Path
* Type (value 4): SRv6 Segment List of the Return Path
* Type (value 5): Structured SRv6 Segment List of the Return Path
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type=3 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(1) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(n) (bottom of stack) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: SR-MPLS Segment List Sub-TLV in Return Path TLV
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type=4 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Segment(1) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Segment(n) (bottom of stack) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: SRv6 Segment List Sub-TLV in Return Path TLV
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type=5 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LB Length | LN Length | Fun. Length | Arg. Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Segment(1) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LB Length | LN Length | Fun. Length | Arg. Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Segment(n) (bottom of stack) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: Structured SRv6 Segment List Sub-TLV in Return Path TLV
An SR-MPLS Label Stack Sub-TLV may carry only Binding SID
[I-D.ietf-pce-binding-label-sid] of the Return SR-MPLS Policy.
An SRv6 Segment List Sub-TLV and Structured SRv6 Segment List Sub-TLV
may carry only Binding SID [I-D.ietf-pce-binding-label-sid] of the
Return SRv6 Policy.
A Structured SRv6 Segment List Sub-TLV is used carry the structure
and behavior for SRv6 SIDs [RFC8986] used in the Return SRv6 path as
shown in Figure 7. The structure is intended for informational use
by the control and management planes. The fields in the structure of
the Sub-TLV are defined as follows [RFC8986]:
* LB Length: 1 octet. SRv6 SID Locator Block (LB) length in bits.
* LN Length: 1 octet. SRv6 SID Locator Node (LN) length in bits.
* Fun. Length: 1 octet. SRv6 SID Function length in bits.
* Arg. Length: 1 octet. SRv6 SID Arguments length in bits.
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In Structured SRv6 Segment List Sub-TLV, the sum of all four sizes
MUST be less than or equal to 128 bits. If the sum of all four sizes
is larger than 128 bits, the Sub-TLV MUST be ignored by the Session-
Reflector.
The Session-Sender MUST only insert one Segment List Return Path Sub-
TLV in the test packet. The Session-Reflector MUST only process the
first Segment List Return Path Sub-TLV in the test packet and ignore
other Segment List Return Path Sub-TLVs if present.
Note that in addition to P2P SR paths, the Return Segment List Sub-
TLV is also applicable to P2MP SR paths. For example, for P2MP SR
paths, it may only carry the Node Segment Identifier of the Session-
Sender in order for the reply test packet to follow an SR path to the
Session-Sender.
5. Security Considerations
The usage of STAMP protocol is intended for deployment in limited
domains [RFC8799]. As such, it assumes that a node involved in STAMP
protocol operation has previously verified the integrity of the path
and the identity of the far-end Session-Reflector.
If desired, attacks can be mitigated by performing basic validation
and sanity checks, at the Session-Sender, of the timestamp fields in
received reply test packets. The minimal state associated with these
protocols also limits the extent of measurement disruption that can
be caused by a corrupt or invalid test packet to a single test cycle.
The security considerations specified in [RFC8762] and [RFC8972] also
apply to the extensions defined in this document. Specifically, the
message integrity protection using HMAC, as defined in [RFC8762]
Section 4.4, also apply to the procedure described in this document.
STAMP uses the well-known UDP port number that could become a target
of denial of service (DoS) or could be used to aid man-in-the-middle
(MITM) attacks. Thus, the security considerations and measures to
mitigate the risk of the attack documented in Section 6 of [RFC8545]
equally apply to the STAMP extensions in this document.
The STAMP extensions defined in this document may be used for
potential "proxying" attacks. For example, a Session-Sender may
specify a return path that has a destination different from that of
the Session-Sender. But normally, such attacks will not happen in an
SR domain where the Session-Senders and Session-Reflectors belong to
the same domain. In order to prevent using the extension defined in
this document for proxying any possible attacks, the return path has
destination to the same node where the forward path is from. The
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Session-Reflector may drop the Session-Sender test packet when it
cannot determine whether the Return Path has the destination to the
Session-Sender. That means, the Session-Sender should choose a
proper source address according to the specified Return Path to help
the Session-Reflector to make that decision.
6. IANA Considerations
IANA has created the "STAMP TLV Types" registry for [RFC8972]. IANA
is requested to allocate a value for the Destination Address TLV Type
and a value for the Return Path TLV Type from the IETF Review TLV
range of the same registry.
+=======+==============================+===============+
| Value | Description | Reference |
+=======+==============================+===============+
| TBA1 | Destination Node Address TLV | This document |
+-------+------------------------------+---------------+
| TBA2 | Return Path TLV | This document |
+-------+------------------------------+---------------+
Table 1: STAMP TLV Types
IANA is requested to create a sub-registry for "Return Path Sub-TLV
Type". All code points in the range 1 through 175 in this registry
shall be allocated according to the "IETF Review" procedure as
specified in [RFC8126]. Code points in the range 176 through 239 in
this registry shall be allocated according to the "First Come First
Served" procedure as specified in [RFC8126]. Remaining code points
are allocated according to Table 2:
+===========+=========================+===============+
| Value | Description | Reference |
+===========+=========================+===============+
| 1 - 175 | IETF Review | This document |
+-----------+-------------------------+---------------+
| 176 - 239 | First Come First Served | This document |
+-----------+-------------------------+---------------+
| 240 - 251 | Experimental Use | This document |
+-----------+-------------------------+---------------+
| 252 - 254 | Private Use | This document |
+-----------+-------------------------+---------------+
Table 2: Return Path Sub-TLV Type Registry
IANA is requested to allocate the values for the following Sub-TLV
Types from this registry.
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+======+========================================+===============+
| Type | Description | Reference |
+======+========================================+===============+
| 0 | Reserved | This document |
+------+----------------------------------------+---------------+
| 1 | Return Path Control Code | This document |
+------+----------------------------------------+---------------+
| 2 | Return Address | This document |
+------+----------------------------------------+---------------+
| 3 | SR-MPLS Label Stack of the Return Path | This document |
+------+----------------------------------------+---------------+
| 4 | SRv6 Segment List of the Return Path | This document |
+------+----------------------------------------+---------------+
| 5 | Structured SRv6 Segment List of the | This document |
| | Return Path | |
+------+----------------------------------------+---------------+
| 255 | Reserved | This document |
+------+----------------------------------------+---------------+
Table 3: Return Path Sub-TLV Types
IANA has created the "STAMP TLV Flags" subregistry. IANA is
requested to allocate the following bit position in the "STAMP TLV
Flags" subregistry.
+==============+========+===================+===============+
| Bit Position | Symbol | Description | Reference |
+==============+========+===================+===============+
| TBA3 | D | Wrong Destination | This document |
+--------------+--------+-------------------+---------------+
Table 4: STAMP TLV Flags
7. References
7.1. 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>.
[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>.
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[RFC8762] Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple
Two-Way Active Measurement Protocol", RFC 8762,
DOI 10.17487/RFC8762, March 2020,
<https://www.rfc-editor.org/info/rfc8762>.
[RFC8972] Mirsky, G., Min, X., Nydell, H., Foote, R., Masputra, A.,
and E. Ruffini, "Simple Two-Way Active Measurement
Protocol Optional Extensions", RFC 8972,
DOI 10.17487/RFC8972, January 2021,
<https://www.rfc-editor.org/info/rfc8972>.
[RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>.
7.2. Informative References
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8545] Morton, A., Ed. and G. Mirsky, Ed., "Well-Known Port
Assignments for the One-Way Active Measurement Protocol
(OWAMP) and the Two-Way Active Measurement Protocol
(TWAMP)", RFC 8545, DOI 10.17487/RFC8545, March 2019,
<https://www.rfc-editor.org/info/rfc8545>.
[RFC8799] Carpenter, B. and B. Liu, "Limited Domains and Internet
Protocols", RFC 8799, DOI 10.17487/RFC8799, July 2020,
<https://www.rfc-editor.org/info/rfc8799>.
[I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", Work in
Progress, Internet-Draft, draft-ietf-spring-segment-
routing-policy-14, 25 October 2021,
<https://www.ietf.org/archive/id/draft-ietf-spring-
segment-routing-policy-14.txt>.
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[I-D.ietf-pce-binding-label-sid]
Sivabalan, S., Filsfils, C., Tantsura, J., Previdi, S.,
and C. L. (editor), "Carrying Binding Label/Segment
Identifier in PCE-based Networks.", Work in Progress,
Internet-Draft, draft-ietf-pce-binding-label-sid-12, 24
January 2022, <https://www.ietf.org/archive/id/draft-ietf-
pce-binding-label-sid-12.txt>.
[I-D.ietf-ippm-stamp-yang]
Mirsky, G., Min, X., and W. S. Luo, "Simple Two-way Active
Measurement Protocol (STAMP) Data Model", Work in
Progress, Internet-Draft, draft-ietf-ippm-stamp-yang-09,
12 July 2021, <https://www.ietf.org/archive/id/draft-ietf-
ippm-stamp-yang-09.txt>.
[IEEE802.1AX]
IEEE Std. 802.1AX, "IEEE Standard for Local and
metropolitan area networks - Link Aggregation", November
2008.
Acknowledgments
The authors would like to thank Thierry Couture for the discussions
on the use-cases for Performance Measurement in Segment Routing. The
authors would also like to thank Greg Mirsky, Mike Koldychev, Gyan
Mishra, Tianran Zhou, Al Mortons, Reshad Rahman, Zhenqiang Li, Frank
Brockners, and Cheng Li for providing comments and suggestions.
Authors' Addresses
Rakesh Gandhi (editor)
Cisco Systems, Inc.
Canada
Email: rgandhi@cisco.com
Clarence Filsfils
Cisco Systems, Inc.
Email: cfilsfil@cisco.com
Daniel Voyer
Bell Canada
Email: daniel.voyer@bell.ca
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Mach(Guoyi) Chen
Huawei
Email: mach.chen@huawei.com
Bart Janssens
Colt
Email: Bart.Janssens@colt.net
Richard Foote
Nokia
Email: footer.foote@nokia.com
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