Simple TWAMP (STAMP) Extensions for Segment Routing Networks
draft-gandhi-ippm-stamp-srpm-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
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|---|---|---|---|
| Authors | Rakesh Gandhi , Clarence Filsfils , Daniel Voyer , Mach Chen , Bart Janssens | ||
| Last updated | 2021-01-12 | ||
| Replaced by | draft-ietf-ippm-stamp-srpm, RFC 9503 | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
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| Additional resources | Mailing list discussion | ||
| Stream | WG state | Call For Adoption By WG Issued | |
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draft-gandhi-ippm-stamp-srpm-01
IPPM Working Group R. Gandhi, Ed.
Internet-Draft C. Filsfils
Intended status: Standards Track Cisco Systems, Inc.
Expires: July 16, 2021 D. Voyer
Bell Canada
M. Chen
Huawei
B. Janssens
Colt
January 12, 2021
Simple TWAMP (STAMP) Extensions for Segment Routing Networks
draft-gandhi-ippm-stamp-srpm-01
Abstract
Segment Routing (SR) leverages the source routing paradigm. SR is
applicable to both Multiprotocol Label Switching (SR-MPLS) and IPv6
(SRv6) data planes. This document specifies RFC 8762 (Simple Two-Way
Active Measurement Protocol (STAMP)) extensions for Delay and Loss
Measurement in Segment Routing networks, for both SR-MPLS and SRv6
data planes.
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 July 16, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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(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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified 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. Probe Query Message . . . . . . . . . . . . . . . . . . . . . 4
3.1. Control Code Field Extension for STAMP Messages . . . . . 4
3.2. Loss Measurement Query Message Extensions . . . . . . . . 5
4. Probe Response Message . . . . . . . . . . . . . . . . . . . 8
4.1. Loss Measurement Response Message Extensions . . . . . . 8
5. Node Address TLV Extensions . . . . . . . . . . . . . . . . . 10
6. Return Path TLV Extensions . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . 14
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
Segment Routing (SR) leverages the source routing paradigm and
greatly simplifies network operations for Software Defined Networks
(SDNs). SR is applicable to both Multiprotocol Label Switching (SR-
MPLS) and IPv6 (SRv6) data planes. Built-in SR Performance
Measurement (PM) is one of the essential requirements to provide
Service Level Agreements (SLAs).
The Simple Two-way Active Measurement Protocol (STAMP) provides
capabilities for the measurement of various performance metrics in IP
networks using probe messages [RFC8762]. It eliminates the need for
control-channel signaling by using configuration data model to
provision a test-channel (e.g. UDP paths).
[I-D.ietf-ippm-stamp-option-tlv] defines TLV extensions for STAMP
messages.
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The STAMP message with a TLV for "direct measurement" can be used for
combined Delay + Loss measurement [I-D.ietf-ippm-stamp-option-tlv].
However, in order to use only for loss measurement purpose, it
requires the node to support the delay measurement messages and
support timestamp for these messages (which may also require clock
synchronization). Furthermore, for hardware-based counter collection
for direct-mode loss measurement, the optional TLV based processing
adds unnecessary overhead (as counters are not at well-known
locations).
This document specifies RFC 8762 (Simple Two-Way Active Measurement
Protocol (STAMP)) extensions for Delay and Loss Measurement in
Segment Routing networks, for both SR-MPLS and SRv6 data planes.
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
BSID: Binding Segment ID.
DM: Delay Measurement.
HMAC: Hashed Message Authentication Code.
LM: Loss Measurement.
MPLS: Multiprotocol Label Switching.
NTP: Network Time Protocol.
OWAMP: One-Way Active Measurement Protocol.
PM: Performance Measurement.
PTP: Precision Time Protocol.
SID: Segment ID.
SL: Segment List.
SR: Segment Routing.
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SRH: Segment Routing Header.
SR-MPLS: Segment Routing with MPLS data plane.
SRv6: Segment Routing with IPv6 data plane.
SSID: STAMP Session Identifier.
STAMP: Simple Two-way Active Measurement Protocol.
2.3. Reference Topology
In the reference topology shown below, the sender node R1 initiates a
performance measurement probe query message and the reflector node R5
sends a probe response message for the query message received. The
probe response message is typically sent to the sender node R1.
t1 t2
/ \
+-------+ Query +-------+
| | - - - - - - - - - ->| |
| R1 |=====================| R5 |
| |<- - - - - - - - - - | |
+-------+ Response +-------+
\ /
t4 t3
Sender Reflector
Reference Topology
3. Probe Query Message
3.1. Control Code Field Extension for STAMP Messages
In this document, the Control Code field is defined for delay and
loss measurement probe query messages for STAMP protocol in
unauthenticated and authenticated modes. The modified delay
measurement probe query message format is shown in Figure 1. This
message format is backwards compatible with the message format
defined in STAMP [RFC8762] as its reflector MUST ignore the received
field (previously identified as MBZ). With this field, the reflector
node does not require any additional state for PM (recall that in SR
networks, the state is in the probe packet and signaling of the
parameters is undesired). The usage of the Control Code is not
limited to the SR and can be used for non-SR network.
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. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | SSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ |Se Control Code|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
Figure 1: Sender Control Code in STAMP DM Message
Sender Control Code: Set as follows in STAMP probe query message.
In a Query:
0x0: Out-of-band Response Requested. Indicates that the probe
response is not required over the same path in the reverse
direction. This is also the default behavior.
0x1: In-band Response Requested. Indicates that this query has
been sent over a bidirectional path and the probe response is
required over the same path in the reverse direction.
0x2: No Response Requested.
3.2. Loss Measurement Query Message Extensions
In this document, STAMP probe query messages for loss measurement are
defined as shown in Figure 2 and Figure 3. The message formats are
hardware efficient due to well-known locations of the counters and
payload small in size. They are stand-alone and similar to the delay
measurement message formats (e.g. location of the Counter and
Timestamp). They also do not require backwards compatibility and
support for the existing DM message formats from [RFC8762] as
different user-configured destination UDP port is used for loss
measurement.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved | Block Number | SSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ |Se Control Code|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| MBZ (24 octets) |
| |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: STAMP LM Probe Query Message - Unauthenticated Mode
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (12 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved | Block Number | SSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ |Se Control Code|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (64 octets) |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| HMAC (16 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: STAMP LM Probe Query Message - Authenticated Mode
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Sequence Number (32-bit): As defined in [RFC8762].
Transmit Counter (64-bit): The number of packets or octets sent by
the sender node in the query message and by the reflector node in the
response message. The counter is always written at the well-known
location in the probe query and response messages.
Receive Counter (64-bit): The number of packets or octets received at
the reflector node. It is written by the reflector node in the probe
response message.
Sender Counter (64-bit): This is the exact copy of the transmit
counter from the received query message. It is written by the
reflector node in the probe response message.
Sender Sequence Number (32-bit): As defined in [RFC8762].
Sender TTL: As defined in [RFC8762].
LM Flags: The meanings of the Flag bits are:
X: Extended counter format indicator. Indicates the use of
extended (64-bit) counter values. Initialized to 1 upon creation
(and prior to transmission) of an LM query and copied from an LM
query to an LM response message. Set to 0 when the LM message is
transmitted or received over an interface that writes 32-bit
counter values.
B: Octet (byte) count. When set to 1, indicates that the Counter
1-4 fields represent octet counts. The octet count applies to all
packets within the LM scope, and the octet count of a packet sent
or received includes the total length of that packet (but excludes
headers, labels, or framing of the channel itself). When set to
0, indicates that the Counter fields represent packet counts.
Block Number (8-bit): The Loss Measurement using Alternate-Marking
method defined in [RFC8321] requires to color the data traffic. To
be able to correlate the transmit and receive traffic counters of the
matching color, the Block Number (or color) of the traffic counters
is carried by the probe query and response messages for loss
measurement. The Block Number can also be used to aggregate
performance metrics collected.
HMAC: The probe message in authenticated mode includes a key Hashed
Message Authentication Code (HMAC) [RFC2104] hash. Each probe query
and response messages are authenticated by adding Sequence Number
with Hashed Message Authentication Code (HMAC) TLV. It can use HMAC-
SHA-256 truncated to 128 bits (similarly to the use of it in IPSec
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defined in [RFC4868]); hence the length of the HMAC field is 16
octets.
HMAC uses its own key and the mechanism to distribute the HMAC key is
outside the scope of this document.
In authenticated mode, only the sequence number is encrypted, and the
other payload fields are sent in clear text. The probe message MAY
include Comp.MBZ (Must Be Zero) variable length field to align the
packet on 16 octets boundary.
4. Probe Response Message
4.1. Loss Measurement Response Message Extensions
In this document, STAMP probe response message formats are defined
for loss measurement as shown in Figure 4 and Figure 5.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved | Block Number | SSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved |Sender Block Nu| MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender TTL | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: STAMP LM Probe Response Message - Unauthenticated Mode
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (12 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved | Block Number | SSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (8 octets) |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (12 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved |Sender Block Nu| MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender TTL | |
+-+-+-+-+-+-+-+-+ |
| MBZ (15 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| HMAC (16 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: STAMP LM Probe Response Message - Authenticated Mode
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5. Node Address TLV Extensions
In this document, Node Address TLV is defined for STAMP message
[I-D.ietf-ippm-stamp-option-tlv] and has the following format shown
in Figure 6:
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Address Family |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Node Address TLV Format
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 STAMP TLV Flags are set using the procedures described in
[I-D.ietf-ippm-stamp-option-tlv].
The following Type is defined and it contains Node Address TLV:
Destination Node Address (value TBA1):
The Destination Node Address TLV is optional. The Destination Node
Address TLV indicates the address of the intended recipient node of
the probe message. The reflector node MUST NOT send response message
if it is not the intended destination node of the probe query
message.
6. Return Path TLV Extensions
For two-way performance measurement, the reflector node needs to send
the probe response message on a specific reverse path. The sender
node can request in the probe query message to the reflector node to
send a response message back on a given reverse path (e.g. co-routed
bidirectional path). This way the reflector node does not require
any additional state for PM (recall that in SR networks, the state is
in the probe packet and signaling of the parameters is undesired).
For one-way performance measurement, the sender node address may not
be reachable via IP route from the reflector node. The sender node
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in this case needs to send its reachability path information to the
reflector node.
[I-D.ietf-ippm-stamp-option-tlv] defines STAMP probe query messages
that can include one or more optional TLVs. The TLV Type (value
TBA2) is defined in this document for Return Path that carries
reverse path for STAMP probe response messages (in the payload of the
message). The format of the Return Path TLV is shown in Figure 7:
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 7: Return Path TLV
The STAMP TLV Flags are set using the procedures described in
[I-D.ietf-ippm-stamp-option-tlv].
The following Type defined for the Return Path TLV contains the Node
Address sub-TLV using the format shown above in Figure 7:
o Type (value 0): Return Address. Target node address of the
response message different than the Source Address in the query
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(1) |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(n) |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: Segment List Sub-TLV in Return Path TLV
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The Segment List Sub-TLV (shown above in Figure 8) in the Return Path
TLV can be one of the following Types:
o Type (value 1): SR-MPLS Label Stack of the Reverse Path
o Type (value 2): SR-MPLS Binding SID
[I-D.ietf-pce-binding-label-sid] of the Reverse SR Policy
o Type (value 3): SRv6 Segment List of the Reverse Path
o Type (value 4): SRv6 Binding SID [I-D.ietf-pce-binding-label-sid]
of the Reverse SR Policy
The Return Path TLV is optional. The sender node MUST only insert
one Return Path TLV in the probe query message and the reflector node
MUST only process the first Return Path TLV in the probe query
message and ignore other Return Path TLVs if present. The reflector
node MUST send probe response message back on the reverse path
specified in the Return Path TLV and MUST NOT add Return Path TLV in
the probe response message.
7. Security Considerations
The performance measurement is intended for deployment in well-
managed private and service provider networks. As such, it assumes
that a node involved in a measurement operation has previously
verified the integrity of the path and the identity of the far-end
reflector node.
If desired, attacks can be mitigated by performing basic validation
and sanity checks, at the sender, of the counter or timestamp fields
in received measurement response messages. The minimal state
associated with these protocols also limits the extent of measurement
disruption that can be caused by a corrupt or invalid message to a
single query/response cycle.
Use of HMAC-SHA-256 in the authenticated mode protects the data
integrity of the probe messages. Cryptographic measures may be
enhanced by the correct configuration of access-control lists and
firewalls.
8. IANA Considerations
IANA will create a "STAMP TLV Type" registry for
[I-D.ietf-ippm-stamp-option-tlv]. IANA is requested to allocate a
value for the following Destination Address TLV Type from the IETF
Review TLV range of this registry. This TLV is to be carried in the
probe messages.
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o Type TBA1: Destination Node Address TLV
IANA is also requested to allocate a value for the following Return
Path TLV Type from the IETF Review TLV range of the same registry.
This TLV is to be carried in the probe query messages.
o Type TBA2: Return Path TLV
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 1:
+-----------+--------------+---------------+
| Value | Description | Reference |
+-----------+--------------+---------------+
| 0 | Reserved | This document |
| 1 - 175 | Unassigned | This document |
| 176 - 239 | Unassigned | This document |
| 240 - 251 | Experimental | This document |
| 252 - 254 | Private Use | This document |
| 255 | Reserved | This document |
+-----------+--------------+---------------+
Table 1: Return Path Sub-TLV Type Registry
IANA is requested to allocate the values for the following Sub-TLV
Types from this registry.
o Type (value 1): Return Address
o Type (value 2): SR-MPLS Label Stack of the Reverse Path
o Type (value 3): SR-MPLS Binding SID
[I-D.ietf-pce-binding-label-sid] of the Reverse SR Policy
o Type (value 4): SRv6 Segment List of the Reverse Path
o Type (value 5): SRv6 Binding SID [I-D.ietf-pce-binding-label-sid]
of the Reverse SR Policy
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9. References
9.1. 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>.
[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>.
[I-D.ietf-ippm-stamp-option-tlv]
Mirsky, G., Min, X., Nydell, H., Foote, R., Masputra, A.,
and E. Ruffini, "Simple Two-way Active Measurement
Protocol Optional Extensions", draft-ietf-ippm-stamp-
option-tlv-09 (work in progress), August 2020.
9.2. Informative References
[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
Hashing for Message Authentication", RFC 2104,
DOI 10.17487/RFC2104, February 1997,
<https://www.rfc-editor.org/info/rfc2104>.
[RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA-
384, and HMAC-SHA-512 with IPsec", RFC 4868,
DOI 10.17487/RFC4868, May 2007,
<https://www.rfc-editor.org/info/rfc4868>.
[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>.
[RFC8321] Fioccola, G., Ed., Capello, A., Cociglio, M., Castaldelli,
L., Chen, M., Zheng, L., Mirsky, G., and T. Mizrahi,
"Alternate-Marking Method for Passive and Hybrid
Performance Monitoring", RFC 8321, DOI 10.17487/RFC8321,
January 2018, <https://www.rfc-editor.org/info/rfc8321>.
Gandhi, et al. Expires April 23, 2021 [Page 14]
Internet-Draft STAMP Extensions for Segment Routing October 2020
[I-D.ietf-pce-binding-label-sid]
Filsfils, C., Sivabalan, S., Tantsura, J., Hardwick, J.,
Previdi, S., and C. Li, "Carrying Binding Label/Segment-ID
in PCE-based Networks.", draft-ietf-pce-binding-label-
sid-03 (work in progress), June 2020.
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 for reviewing this
document and providing useful comments and suggestions. The authors
would like to acknowledge the earlier work on the loss measurement
using TWAMP described in draft-xiao-ippm-twamp-ext-direct-loss.
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
Mach(Guoyi) Chen
Huawei
Email: mach.chen@huawei.com
Bart Janssens
Colt
Email: Bart.Janssens@colt.net
Gandhi, et al. Expires April 23, 2021 [Page 15]