Performance Measurement Using TWAMP Light and STAMP for Segment Routing Networks
draft-gandhi-spring-twamp-srpm-06
The information below is for an old version of the document.
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|---|---|---|---|
| Authors | Rakesh Gandhi , Clarence Filsfils , Daniel Voyer , Mach Chen , Bart Janssens | ||
| Last updated | 2020-03-01 (Latest revision 2019-12-05) | ||
| Replaced by | draft-gandhi-spring-stamp-srpm | ||
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draft-gandhi-spring-twamp-srpm-06
SPRING Working Group R. Gandhi, Ed.
Internet-Draft C. Filsfils
Intended status: Standards Track Cisco Systems, Inc.
Expires: September 2, 2020 D. Voyer
Bell Canada
M. Chen
Huawei
B. Janssens
Colt
March 1, 2020
Performance Measurement Using TWAMP Light and STAMP for Segment Routing
Networks
draft-gandhi-spring-twamp-srpm-06
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 procedure for sending
and processing probe query and response messages for Performance
Measurement (PM) in Segment Routing networks. The procedure uses the
mechanisms defined in RFC 5357 (Two-Way Active Measurement Protocol
(TWAMP) Light) and Simple Two-Way Active Measurement Protocol (STAMP)
for Delay Measurement, and also uses the extensions defined in this
document for Loss Measurement. The procedure specified is applicable
to SR-MPLS and SRv6 data planes and is used for both links and end-
to-end SR Policies.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on September 2, 2020.
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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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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Reference Topology . . . . . . . . . . . . . . . . . . . 5
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Example Provisioning Model . . . . . . . . . . . . . . . 6
3.2. STAMP Applicability . . . . . . . . . . . . . . . . . . . 7
4. Probe Messages . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Probe Query Message . . . . . . . . . . . . . . . . . . . 7
4.1.1. Delay Measurement Query Message . . . . . . . . . . . 7
4.1.2. Loss Measurement Query Message . . . . . . . . . . . 9
4.1.3. Loss Measurement Query Message Formats for TWAMP . . 10
4.1.4. Loss Measurement Query Message Formats for STAMP . . 13
4.1.5. Probe Query for SR Links . . . . . . . . . . . . . . 14
4.1.6. Probe Query for End-to-end Measurement for SR Policy 14
4.2. Probe Response Message . . . . . . . . . . . . . . . . . 16
4.2.1. One-way Measurement Mode . . . . . . . . . . . . . . 16
4.2.2. Two-way Measurement Mode . . . . . . . . . . . . . . 16
4.2.3. Loopback Measurement Mode . . . . . . . . . . . . . . 18
4.2.4. Loss Measurement Response Message Formats for TWAMP . 18
4.2.5. Loss Measurement Response Message Formats for STAMP . 20
4.3. Node Address TLV for STAMP . . . . . . . . . . . . . . . 23
4.4. Return Path TLV for STAMP . . . . . . . . . . . . . . . . 23
5. Performance Measurement for P2MP SR Policies . . . . . . . . 25
6. ECMP Support for SR Policies . . . . . . . . . . . . . . . . 26
7. Additional Message Processing Rules . . . . . . . . . . . . . 26
7.1. TTL and Hop Limit . . . . . . . . . . . . . . . . . . . . 26
7.2. Router Alert Option . . . . . . . . . . . . . . . . . . . 26
7.3. UDP Checksum . . . . . . . . . . . . . . . . . . . . . . 27
8. Security Considerations . . . . . . . . . . . . . . . . . . . 27
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9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
10.1. Normative References . . . . . . . . . . . . . . . . . . 28
10.2. Informative References . . . . . . . . . . . . . . . . . 29
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 32
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 32
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. SR takes advantage of the Equal-
Cost Multipaths (ECMPs) between source and transit nodes, between
transit nodes and between transit and destination nodes. 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. Built-in SR Performance Measurement (PM) is one of the
essential requirements to provide Service Level Agreements (SLAs).
The One-Way Active Measurement Protocol (OWAMP) defined in [RFC4656]
and Two-Way Active Measurement Protocol (TWAMP) defined in [RFC5357]
provide capabilities for the measurement of various performance
metrics in IP networks using probe messages. These protocols rely on
control-channel signaling to establish a test-channel over an UDP
path. These protocols lack support for direct-mode Loss Measurement
(LM) to detect actual data traffic loss which is required in SR
networks. The Simple Two-way Active Measurement Protocol (STAMP)
[I-D.ietf-ippm-stamp] alleviates the control-channel signaling by
using configuration data model to provision a test-channel. The
TWAMP Light [Appendix I in RFC5357] [BBF.TR-390] provides simplified
mechanisms for active performance measurement in Customer IP networks
by provisioning UDP paths and eliminates the control-channel
signaling.
This document specifies procedures for sending and processing probe
query and response messages for Performance Measurement in SR
networks. The procedure uses the mechanisms defined in [RFC5357]
(TWAMP Light) and STAMP for Delay Measurement (DM), and also uses the
extensions defined in this document for Loss Measurement. The
procedure specified is applicable to SR-MPLS and SRv6 data planes and
are used for both links and end-to-end SR Policies. This document
also defines mechanisms for handling ECMPs of SR Policies for
performance delay measurement.
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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.
ECMP: Equal Cost Multi-Path.
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.
PSID: Path Segment Identifier.
PTP: Precision Time Protocol.
SID: Segment ID.
SL: Segment List.
SR: Segment Routing.
SRH: Segment Routing Header.
SR-MPLS: Segment Routing with MPLS data plane.
SRv6: Segment Routing with IPv6 data plane.
STAMP: Simple Two-way Active Measurement Protocol.
TC: Traffic Class.
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TWAMP: Two-Way Active Measurement Protocol.
2.3. Reference Topology
In the reference topology shown below, the sender node R1 initiates a
probe query for performance measurement and the reflector node R5
sends a probe response for the query message received. The probe
response is sent to the sender node R1. The nodes R1 and R5 may be
directly connected via a link enabled with Segment Routing or there
exists a Point-to-Point (P2P) SR Policy
[I-D.ietf-spring-segment-routing-policy] on node R1 with destination
to node R5. In case of Point-to-Multipoint (P2MP), SR Policy
originating from source node R1 may terminate on multiple destination
leaf nodes [I-D.voyer-spring-sr-replication-segment].
+-------+ Query +-------+
| | - - - - - - - - - ->| |
| R1 |---------------------| R5 |
| |<- - - - - - - - - - | |
+-------+ Response +-------+
Sender Reflector
Reference Topology
3. Overview
For one-way, two-way and round-trip delay measurements in Segment
Routing networks, the TWAMP Light procedures defined in Appendix I of
[RFC5357] are used. For one-way and two-way direct-mode and
inferred-mode loss measurements in Segment Routing networks, the
procedures defined in this document are used. One-way loss
measurement provides receive packet loss whereas two-way loss
measurement provides both transmit and receive packet loss. Separate
UDP destination port numbers are user-configured for delay and loss
measurements from the range specified in [I-D.ietf-ippm-stamp]. The
sender uses the UDP port number following the guidelines specified in
Section 6 in [RFC6335]. For both links and end-to-end SR Policies,
no PM session for delay or loss measurement is created on the
reflector node R5 [RFC5357].
For Performance Measurement, probe query and response messages are
sent as following:
o For Delay Measurement, the probe messages are sent on the
congruent path of the data traffic by the sender node, and are
used to measure the delay experienced by the actual data traffic
flowing on the links and SR Policies.
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o For Loss Measurement, the probe messages are sent on the congruent
path of the data traffic by the sender node, and are used to
collect the receive traffic counters for the incoming link or
incoming SID where the probe query messages are received at the
reflector node (incoming link or incoming SID needed since the
reflector node does not have PM session state present).
The In-Situ Operations, Administration, and Maintenance (IOAM)
mechanisms for SR-MPLS defined in [I-D.gandhi-spring-ioam-sr-mpls]
and for SRv6 defined in [I-D.ali-spring-ioam-srv6] are used to carry
PM information such as timestamp in-band as part of the data packets,
and are outside the scope of this document.
3.1. Example Provisioning Model
An example of a provisioning model and typical measurement parameters
for performance delay and loss measurements is shown in the following
Figure:
+------------+
| Controller |
+------------+
Measurement Protocol / \ Measurement Protocol
Destination UDP Port / \ Destination UDP port
Measurement Type / \ Measurement Type
Delay/Loss / \ Delay/Loss
Authentication Mode & Key / \ Authentication Mode & Key
Timestamp Format / \ Loss Measurement Mode
Delay Measurement Mode / \
Padding/MBZ Bytes / \
Loss Measurement Mode / \
v v
+-------+ +-------+
| | | |
| R1 |------------| R5 |
| | | |
+-------+ +-------+
Sender Reflector
Example Provisioning Model
The reflector node R5 uses the parameters for the timestamp format,
delay measurement mode (i.e. one-way, two-way or loopback mode) and
packet padding size from the received probe query message.
Examples of Measurement Protocol is TWAMP Light or STAMP, the
Timestamp Format is PTPv2 [IEEE1588] or NTP and the Loss Measurement
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mode is inferred or direct mode. The mechanisms to provision the
sender and reflector nodes are outside the scope of this document.
3.2. STAMP Applicability
The Simple Two-way Active Measurement Protocol (STAMP)
[I-D.ietf-ippm-stamp] and the STAMP TLVs
[I-D.ietf-ippm-stamp-option-tlv] are both equally applicable to the
procedures specified in this document. This is because the delay
measurement message formats defined for STAMP are backwards
compatible with the delay measurement message formats defined in
[RFC5357]. The STAMP with a TLV for "direct measurement" can be used
for combined delay + loss measurement using a different user-
configured UDP destination port.
4. Probe Messages
4.1. Probe Query Message
In this document, the probe messages defined in [RFC5357] are used
for Delay and Loss measurements for SR links and end-to-end SR
Policies. The user-configured destination UDP ports (separate UDP
ports for different delay and loss message formats) are used for
identifying the PM probe packets as described in Appendix I of
[RFC5357].
The Sender IPv4 or IPv6 address is used as the source address. When
known, the reflector IPv4 or IPv6 address is used as the destination
address. If not known, the address in the range of 127/8 for IPv4 or
0:0:0:0:0:FFFF:7F00/104 for IPv6 is used as destination address.
This is the case for example, when using SR Policy with IPv4 endpoint
of 0.0.0.0 or IPv6 endpoint of ::0
[I-D.ietf-spring-segment-routing-policy].
4.1.1. Delay Measurement Query Message
The message content for Delay Measurement probe query message using
UDP header [RFC0768], is shown in Figure 1. The DM probe query
message is sent with user-configured Destination UDP port number for
DM. The Destination UDP port cannot be used as Source port, since
the message does not have any indication to distinguish between query
and response. The DM probe query message contains the payload for
delay measurement defined in Section 4.1.2 of [RFC5357]. For
symmetrical size query and response messages [RFC6038], the DM probe
query message contains the payload format defined in Section 4.2.1 of
[RFC5357].
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+---------------------------------------------------------------+
| IP Header |
. Source IP Address = Sender IPv4 or IPv6 Address .
. Destination IP Address = Reflector IPv4 or IPv6 Address .
. Protocol = UDP .
. .
+---------------------------------------------------------------+
| UDP Header |
. Source Port = As chosen by Sender .
. Destination Port = User-configured Port for Delay Measurement.
. .
+---------------------------------------------------------------+
| Payload = Message as specified in Section 4.2.1 of RFC 5357 | |
. Payload = Message as specified in Section 4.1.2 of RFC 5357 | .
. Payload = Message specified in Section 4.2 of ietf-ippm-stamp .
. .
+---------------------------------------------------------------+
Figure 1: DM Probe Query Message
Timestamp field is eight bytes and use the format defined in
Section 4.2.1 of [RFC5357]. It is recommended to use the IEEE 1588v2
Precision Time Protocol (PTP) truncated 64-bit timestamp format
[IEEE1588] as specified in [RFC8186], with hardware support in
Segment Routing networks.
4.1.1.1. Control Code Field in TWAMP and STAMP Message
The Control Code field is defined in the modified DM probe message
format as follows for both TWAMP and STAMP packet formats in
unautenticated an authenticated modes. This DM probe message format
is backwards compatible with the format defined in [RFC5357] as its
reflector MUST ignore the received MBZ field.
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. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
Control Code: Set as follows in TWAMP and STAMP probe query and
response messages.
For 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.
For a Response:
0x1: Error - Invalid Message. Indicates that the operation
failed because the received query message was malformed.
Reserved: Reserved for future use.
4.1.1.2. Delay Measurement Authentication Mode
When using the authenticated mode for delay measurement, the matching
authentication type (e.g. HMAC-SHA-256) and key are user-configured
on both the sender and reflector nodes. A separate user-configured
destination UDP port is used for the delay measurement in
authentication mode due to the different probe message format.
4.1.2. Loss Measurement Query Message
The message content for Loss Measurement probe query message using
UDP header [RFC0768] is shown in Figure 2. The LM probe query
message is sent with user-configured Destination UDP port number for
LM. Separate Destination UDP ports are used for direct-mode and
inferred-mode loss measurements. The Destination UDP port cannot be
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used as Source port, since the message does not have any indication
to distinguish between query and response. The LM probe query
message contains the payload for loss measurement as defined in
Figure 3-6.
+---------------------------------------------------------------+
| IP Header |
. Source IP Address = Sender IPv4 or IPv6 Address .
. Destination IP Address = Reflector IPv4 or IPv6 Address .
. Protocol = UDP .
. .
+---------------------------------------------------------------+
| UDP Header |
. Source Port = As chosen by Sender .
. Destination Port = User-configured Port for Loss Measurement .
. .
+---------------------------------------------------------------+
| Payload = Message as specified in Figure 3 or 4 | |
. Payload = Message as specified in Figure 5 or 6 .
. .
+---------------------------------------------------------------+
Figure 2: LM Probe Query Message
4.1.2.1. Loss Measurement Authentication Mode
When using the authenticated mode for loss measurement, the matching
authentication type (e.g. HMAC-SHA-256) and key are user-configured
on both the sender and reflector nodes. A separate user-configured
destination UDP port is used for the loss measurement in
authentication mode due to the different message format.
4.1.3. Loss Measurement Query Message Formats for TWAMP
In this document, TWAMP probe query message formats are defined for
loss measurement as shown in Figure 3 and 4. The message formats are
hardware efficient due to the small size payload and well-known
locations of counters. They are similar to the delay measurement
message formats and do not require any backwards compatibility and
support for the existing DM message formats from [RFC5357].
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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 | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. Packet Padding .
. .
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Checksum Complement |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: LM Probe Query Message Format
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 | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HMAC (16 octets) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. Packet Padding .
. .
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Checksum Complement |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: LM Probe Query Message Format - Authenticated Mode
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Sequence Number (32-bit): As defined in [RFC5357].
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 fixed
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 [RFC5357].
Sender TTL: As defined in [RFC5357].
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. 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 compare 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.
HMAC: The PM probe packet 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
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IPSec 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 packet MAY
include Comp.MBZ (Must Be Zero) variable length field to align the
packet on 16 octets boundary.
4.1.4. Loss Measurement Query Message Formats for STAMP
In this document, STAMP probe query message formats are defined for
loss measurement as shown in Figures 5 and 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved | Block Number | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| MBZ (28 octets) |
| |
| |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: STAMP LM Probe Query Message Format
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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 | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| MBZ (68 octets) |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HMAC (16 octets) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: STAMP LM Probe Query Message Format - Authenticated Mode
4.1.5. Probe Query for SR Links
The probe query message as defined in Figure 1 is sent on the
congruent path of the data traffic for Delay measurement. The probe
query message as defined in Figure 2 is sent on the congruent path of
the data traffic for Loss measurement.
4.1.6. Probe Query for End-to-end Measurement for SR Policy
The performance delay and loss measurement for segment routing is
applicable to both SR-MPLS and SRv6 Policies.
4.1.6.1. Probe Query Message for SR-MPLS Policy
The probe query messages for end-to-end performance measurement of an
SR-MPLS Policy is sent using its SR-MPLS header containing the MPLS
segment list as shown in Figure 7.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(n) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PSID | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message as shown in Figure 1 for DM or Figure 2 for LM |
. .
+---------------------------------------------------------------+
Figure 7: Probe Query Message for SR-MPLS Policy
The Segment List (SL) can be empty to indicate Implicit NULL label
case for a single-hop SR Policy.
The Path Segment Identifier (PSID)
[I-D.ietf-spring-mpls-path-segment] of the SR-MPLS Policy is used for
accounting received traffic on the egress node for loss measurement.
4.1.6.2. Probe Query Message for SRv6 Policy
An SRv6 Policy setup using the SRv6 Segment Routing Header (SRH) and
a Segment List as defined in [I-D.ietf-6man-segment-routing-header].
For SRv6, network programming is defined in
[I-D.ietf-spring-srv6-network-programming]. The probe query messages
for end-to-end performance measurement of an SRv6 Policy is sent
using its SRH with Segment List as shown in Figure 8.
+---------------------------------------------------------------+
| SRH |
. .
+---------------------------------------------------------------+
| Message as shown in Figure 1 for DM or Figure 2 for LM |
. (Using IPv6 Source and Destination Addresses) .
. .
+---------------------------------------------------------------+
Figure 8: Probe Query Message for SRv6 Policy
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For delay measurement of SRv6 Policy using SRH, END function END.OTP
[I-D.ietf-6man-spring-srv6-oam] is used with the target SRv6 SID to
punt probe messages on the target node, as shown in Figure 8.
Similarly, for loss measurement of SRv6 Policy, END function END.OP
[I-D.ietf-6man-spring-srv6-oam] is used with target SRv6 SID to punt
probe messages on the target node.
4.2. Probe Response Message
The probe response message is sent using the IP/UDP information from
the received probe query message. The content of the probe response
message is shown in Figure 9.
+---------------------------------------------------------------+
| IP Header |
. Source IP Address = Reflector IPv4 or IPv6 Address .
. Destination IP Address = Source IP Address from Query .
. Protocol = UDP .
. .
+---------------------------------------------------------------+
| UDP Header |
. Source Port = As chosen by Reflector .
. Destination Port = Source Port from Query .
. .
+---------------------------------------------------------------+
| DM Payload as specified in Section 4.2.1 of RFC 5357 | |
. DM payload as specified in Section 4.3 of ietf-ippm-stamp | .
. LM Payload as specified in Figure 12 or 13 in this document | .
. LM Payload as specified in Figure 14 or 15 in this document | .
. .
+---------------------------------------------------------------+
Figure 9: Probe Response Message
4.2.1. One-way Measurement Mode
In one-way performance measurement mode, the probe response message
as defined in Figure 9 is sent back out-of-band to the sender node,
for both SR links and SR Policies. The Control Code is set to "Out-
of-band Response Requested".
4.2.2. Two-way Measurement Mode
In two-way performance measurement mode, when using a bidirectional
path, the probe response message as defined in Figure 9 is sent back
to the sender node on the congruent path of the data traffic on the
same reverse direction SR Link or associated reverse SR Policy
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[I-D.ietf-pce-sr-bidir-path]. The Control Code is set to "In-band
Response Requested".
Specifically, the probe response message is sent back on the incoming
physical interface where the probe query message is received. This
is useful for example, in case of two-way measurement mode for SR
link delay.
4.2.2.1. Probe Response Message for SR-MPLS Policy
The message content for sending probe response message for two-way
end-to-end performance measurement of an SR-MPLS Policy is shown in
Figure 10.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(n) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message as shown in Figure 9 |
. .
+---------------------------------------------------------------+
Figure 10: Probe Response Message for SR-MPLS Policy
The Path Segment Identifier (PSID)
[I-D.ietf-spring-mpls-path-segment] of the forward SR Policy in the
probe query can be used to find the associated reverse SR Policy
[I-D.ietf-pce-sr-bidir-path] to send the probe response message for
two-way measurement of SR Policy unless when using STAMP with Return
Path TLV.
4.2.2.2. Probe Response Message for SRv6 Policy
The message content for sending probe response message on the
congruent path of the data traffic for two-way end-to-end performance
measurement of an SRv6 Policy with SRH is shown in Figure 11.
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+---------------------------------------------------------------+
| SRH |
. .
+---------------------------------------------------------------+
| Message as shown in Figure 9 |
. (Using IPv6 Source and Destination Addresses) .
. .
+---------------------------------------------------------------+
Figure 11: Probe Response Message for SRv6 Policy
4.2.3. Loopback Measurement Mode
The Loopback measurement mode can be used to measure round-trip delay
for a bidirectional SR Path. The IP header of the probe query
message contains the destination address equals to the sender address
and the source address equals to the reflector address. Optionally,
the probe query message can carry the reverse path information (e.g.
reverse path label stack for SR-MPLS) as part of the SR header. The
reflector node does not process the PM probe messages and generate
response messages.
4.2.4. Loss Measurement Response Message Formats for TWAMP
In this document, TWAMP probe response message formats are defined
for loss measurement as shown in Figure 12 and 13. The message
formats are hardware efficient due to the small size payload and well
known locations of the counters. They are also similar to the delay
measurement message formats.
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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 | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved |Sender Block Nu| MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender TTL | |
+-+-+-+-+-+-+-+-+ +
| Packet Padding |
. .
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Checksum Complement |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 12: LM Probe Response Message Format
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 | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Counter |
| |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Packet Padding .
. .
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Checksum Complement |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 13: LM Probe Response Message Format - Authenticated Mode
4.2.5. Loss Measurement Response Message Formats for STAMP
In this document, STAMP probe response message formats are defined
for loss measurement as shown in Figure 14 and 15.
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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 | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Counter |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|B| Reserved |Sender Block Nu| MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ses-Sender TTL| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 14: STAMP LM Probe Response Message Format
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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 | Reserved | Control Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ses-Sender TTL| |
+-+-+-+-+-+-+-+-+ +
| MBZ (15 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HMAC (16 octets) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 15: STAMP LM Probe Response Message Format - Authenticated
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4.3. Node Address TLV for STAMP
The Node Address TLV is defined for STAMP
[I-D.ietf-ippm-stamp-option-tlv] in this document and has the
following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Address Family |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 16: 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 following Type is defined in this document and it ontains Node
Address TLV:
Destination Node Address (value TBA2):
The Destination Node Address TLV is optional. The Destination Node
Address TLV indicates the address of the intended recipient of the
probe message. The destination node SHOULD NOT send response if it
is not the intended destination node of the probe query message.
This check is useful for example, for performance measurement of SR
Policy when using the destination address in 127/8 range for IPv4 or
in 0:0:0:0:0:FFFF:7F00/104 range for IPv6.
4.4. Return Path TLV for STAMP
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 back on a given reverse path (e.g. co-routed
bidirectional path). This way the destination node does not require
any additional SR Policy state.
For one-way performance measurement, the sender node address may not
be reachable via IP route from the reflector node. The sender node
in this case needs to send its reachability path information to the
reflector node.
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[I-D.ietf-ippm-stamp-option-tlv] defines STAMP probe query messages
that can include one or more optional TLVs. The TLV Type (value
TBA1) is defined in this document for Return Path to carry reverse
path for probe response messages (in the payload of the message).
The format of the Return Path TLV is shown in Figure 17:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = TBA1 | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Return Path Sub-TLVs |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 17: Return Path TLV
The following Type defined for the Return Path TLV contains the Node
Address sub-TLV (shown in Figure 16):
o Type (value 0): Return Address. Target node address of the
response 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(1) |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Segment(n) |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 18: Segment List Sub-TLV in Return Path TLV
The Segment List Sub-TLV (shown in Figure 18) in the Return Path TLV
can be one of the following Types:
o Type (value 1): SR-MPLS Label Stack of the Reverse SR Path
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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 SR 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 PM 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.
5. Performance Measurement for P2MP SR Policies
The procedures for delay and loss measurement described in this
document for Point-to-Point (P2P) SR Policies
[I-D.ietf-spring-segment-routing-policy] are also equally applicable
to the Point-to-Multipoint (P2MP) SR Policies as following:
o The sender root node sends probe query messages using the
Replication Segment defined in
[I-D.voyer-spring-sr-replication-segment] for the P2MP SR Policy
as shown in Figure 19.
o Each reflector leaf node sends its IP address in the Source
Address of the probe response messages as shown in Figure 9. This
allows the sender root node to identify the reflector leaf nodes
of the P2MP SR Policy.
o The P2MP root node measures the end-to-end delay and loss
performance for each P2MP leaf node of the P2MP SR Policy.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Replication SID | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message as shown in Figure 1 for DM or Figure 2 for LM |
. .
+---------------------------------------------------------------+
Figure 19: With Replication Segment for SR-MPLS Policy
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6. ECMP Support for SR Policies
An SR Policy can have ECMPs between the source and transit nodes,
between transit nodes and between transit and destination nodes.
Usage of Anycast SID [RFC8402] by an SR Policy can result in ECMP
paths via transit nodes part of that Anycast group. The PM probe
messages need to be sent to traverse different ECMP paths to measure
performance delay of an SR Policy.
Forwarding plane has various hashing functions available to forward
packets on specific ECMP paths. The mechanisms described in
[RFC8029] and [RFC5884] for handling ECMPs are also applicable to the
performance measurement. In the IP header of the PM probe messages,
sweeping of Destination Addresses in 127/8 range for IPv4 or
0:0:0:0:0:FFFF:7F00/104 range for IPv6 can be used to exercise
particular ECMP paths. As specified in [RFC6437], Flow Label field
in the IPv6 header can also be used for sweeping.
The considerations for performance loss measurement for different
ECMP paths of an SR Policy are outside the scope of this document.
7. Additional Message Processing Rules
7.1. TTL and Hop Limit
The TTL field in the IPv4 and MPLS headers of the probe query
messages is set to 255 [RFC5357]. Similarly, the Hop Limit field in
the IPv6 and SRH headers of the probe query messages is set to 255
[RFC5357].
When using the Destination IPv4 Address from the 127/8 range, the TTL
in the IPv4 header is set to 1 [RFC8029]. Similarly, when using the
Destination IPv6 Address from the 0:0:0:0:0:FFFF:7F00/104 range, the
Hop Limit field in the inner IPv6 header is set to 1 whereas in the
outer IPv6 header is set to 255.
For SR link performance delay and loss measurement, the probe
messages are pre-routed over the link and the TTL and Hop Limit field
are set to 1 in both one-way and two-way measurement modes.
7.2. Router Alert Option
The Router Alert IP option is not set when using the routable
Destination IP Address in the probe messages.
When using the Destination IPv4 Address from the 127/8 range, to be
able to punt probe packets on the reflector node, the Router Alert IP
Option of value 0x0 [RFC2113] for IPv4 MAY be added [RFC8029].
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Similarly, when using the Destination IPv6 Address from the
0:0:0:0:0:FFFF:7F00/104 range, the Router Alert IP Option of value 69
[RFC7506] for IPv6 MAY be added in the destination option header,
Section 4.6 of [RFC8200]. For SRv6 Policy using SRH, it is added in
the inner IPv6 header.
7.3. UDP Checksum
The Checksum Complement for delay and loss measurement messages
follows the procedure defined in [RFC7820] and can be optionally used
with the procedures defined in this document.
For IPv4 and IPv6 probe messages, where the hardware is not capable
of re-computing the UDP checksum or adding checksum complement
[RFC7820], the sender node sets the UDP checksum to 0 [RFC6936]
[RFC8085]. The receiving node bypasses the checksum validation and
accepts the packets with UDP checksum value 0 for the UDP port being
used for PM delay and loss measurements.
8. 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. SRv6 has HMAC protection
authentication defined for SRH
[I-D.ietf-6man-segment-routing-header]. Hence, PM probe messages for
SRv6 may not need authentication mode. Cryptographic measures may be
enhanced by the correct configuration of access-control lists and
firewalls.
9. IANA Considerations
IANA is requested to allocate a value for the following optional
Return Path TLV Type for [I-D.ietf-ippm-stamp-option-tlv] to be
carried in PM probe query messages:
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o Type TBA1: Return Path TLV
IANA is also requested to allocate the values for the following Sub-
TLV Types for the Return Path TLV.
o Type (value 0): Return Address
o Type (value 1): SR-MPLS Label Stack of the Reverse SR 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 SR Path
o Type (value 4): SRv6 Binding SID [I-D.ietf-pce-binding-label-sid]
of the Reverse SR Policy
IANA is requested to allocate a value for the following optional
Destination Address TLV Type for [I-D.ietf-ippm-stamp-option-tlv] to
be carried in PM probe message:
o Type TBA2: Destination Node Address TLV
10. References
10.1. Normative References
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
DOI 10.17487/RFC0768, August 1980,
<https://www.rfc-editor.org/info/rfc768>.
[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>.
[RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M.
Zekauskas, "A One-way Active Measurement Protocol
(OWAMP)", RFC 4656, DOI 10.17487/RFC4656, September 2006,
<https://www.rfc-editor.org/info/rfc4656>.
[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, DOI 10.17487/RFC5357, October 2008,
<https://www.rfc-editor.org/info/rfc5357>.
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[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>.
[I-D.ietf-6man-spring-srv6-oam]
Ali, Z., Filsfils, C., Matsushima, S., Voyer, D., and M.
Chen, "Operations, Administration, and Maintenance (OAM)
in Segment Routing Networks with IPv6 Data plane (SRv6)",
draft-ietf-6man-spring-srv6-oam-03 (work in progress),
December 2019.
[I-D.ietf-ippm-stamp]
Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple
Two-way Active Measurement Protocol", draft-ietf-ippm-
stamp-10 (work in progress), October 2019.
[I-D.ietf-ippm-stamp-option-tlv]
Mirsky, G., Xiao, M., Nydell, H., Foote, R., Masputra, A.,
and E. Ruffini, "Simple Two-way Active Measurement
Protocol Optional Extensions", draft-ietf-ippm-stamp-
option-tlv-03 (work in progress), February 2020.
10.2. Informative References
[IEEE1588]
IEEE, "1588-2008 IEEE Standard for a Precision Clock
Synchronization Protocol for Networked Measurement and
Control Systems", March 2008.
[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>.
[RFC2113] Katz, D., "IP Router Alert Option", RFC 2113,
DOI 10.17487/RFC2113, February 1997,
<https://www.rfc-editor.org/info/rfc2113>.
[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>.
[RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
"Bidirectional Forwarding Detection (BFD) for MPLS Label
Switched Paths (LSPs)", RFC 5884, DOI 10.17487/RFC5884,
June 2010, <https://www.rfc-editor.org/info/rfc5884>.
Gandhi, et al. Expires September 2, 2020 [Page 29]
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[RFC6038] Morton, A. and L. Ciavattone, "Two-Way Active Measurement
Protocol (TWAMP) Reflect Octets and Symmetrical Size
Features", RFC 6038, DOI 10.17487/RFC6038, October 2010,
<https://www.rfc-editor.org/info/rfc6038>.
[RFC6335] Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S.
Cheshire, "Internet Assigned Numbers Authority (IANA)
Procedures for the Management of the Service Name and
Transport Protocol Port Number Registry", BCP 165,
RFC 6335, DOI 10.17487/RFC6335, August 2011,
<https://www.rfc-editor.org/info/rfc6335>.
[RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme,
"IPv6 Flow Label Specification", RFC 6437,
DOI 10.17487/RFC6437, November 2011,
<https://www.rfc-editor.org/info/rfc6437>.
[RFC6936] Fairhurst, G. and M. Westerlund, "Applicability Statement
for the Use of IPv6 UDP Datagrams with Zero Checksums",
RFC 6936, DOI 10.17487/RFC6936, April 2013,
<https://www.rfc-editor.org/info/rfc6936>.
[RFC7506] Raza, K., Akiya, N., and C. Pignataro, "IPv6 Router Alert
Option for MPLS Operations, Administration, and
Maintenance (OAM)", RFC 7506, DOI 10.17487/RFC7506, April
2015, <https://www.rfc-editor.org/info/rfc7506>.
[RFC7820] Mizrahi, T., "UDP Checksum Complement in the One-Way
Active Measurement Protocol (OWAMP) and Two-Way Active
Measurement Protocol (TWAMP)", RFC 7820,
DOI 10.17487/RFC7820, March 2016,
<https://www.rfc-editor.org/info/rfc7820>.
[RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
Switched (MPLS) Data-Plane Failures", RFC 8029,
DOI 10.17487/RFC8029, March 2017,
<https://www.rfc-editor.org/info/rfc8029>.
[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage
Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085,
March 2017, <https://www.rfc-editor.org/info/rfc8085>.
[RFC8186] Mirsky, G. and I. Meilik, "Support of the IEEE 1588
Timestamp Format in a Two-Way Active Measurement Protocol
(TWAMP)", RFC 8186, DOI 10.17487/RFC8186, June 2017,
<https://www.rfc-editor.org/info/rfc8186>.
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[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
[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>.
[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>.
[I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Sivabalan, S., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", draft-
ietf-spring-segment-routing-policy-06 (work in progress),
December 2019.
[I-D.voyer-spring-sr-replication-segment]
Voyer, D., Filsfils, C., Parekh, R., Bidgoli, H., and Z.
Zhang, "SR Replication Segment for Multi-point Service
Delivery", draft-voyer-spring-sr-replication-segment-02
(work in progress), November 2019.
[I-D.ietf-spring-mpls-path-segment]
Cheng, W., Li, H., Chen, M., Gandhi, R., and R. Zigler,
"Path Segment in MPLS Based Segment Routing Network",
draft-ietf-spring-mpls-path-segment-02 (work in progress),
February 2020.
[I-D.ietf-6man-segment-routing-header]
Filsfils, C., Dukes, D., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", draft-ietf-6man-segment-routing-header-26 (work in
progress), October 2019.
[I-D.ietf-spring-srv6-network-programming]
Filsfils, C., Camarillo, P., Leddy, J., Voyer, D.,
Matsushima, S., and Z. Li, "SRv6 Network Programming",
draft-ietf-spring-srv6-network-programming-10 (work in
progress), February 2020.
Gandhi, et al. Expires September 2, 2020 [Page 31]
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[I-D.ietf-pce-binding-label-sid]
Sivabalan, S., Filsfils, C., Tantsura, J., Hardwick, J.,
Previdi, S., and C. Li, "Carrying Binding Label/Segment-ID
in PCE-based Networks.", draft-ietf-pce-binding-label-
sid-01 (work in progress), November 2019.
[BBF.TR-390]
"Performance Measurement from IP Edge to Customer
Equipment using TWAMP Light", BBF TR-390, May 2017.
[I-D.gandhi-spring-ioam-sr-mpls]
Gandhi, R., Ali, Z., Filsfils, C., Brockners, F., Wen, B.,
and V. Kozak, "Segment Routing with MPLS Data Plane
Encapsulation for In-situ OAM Data", draft-gandhi-spring-
ioam-sr-mpls-02 (work in progress), August 2019.
[I-D.ali-spring-ioam-srv6]
Ali, Z., Gandhi, R., Filsfils, C., Brockners, F., Kumar,
N., Pignataro, C., Li, C., Chen, M., and G. Dawra,
"Segment Routing Header encapsulation for In-situ OAM
Data", draft-ali-spring-ioam-srv6-02 (work in progress),
November 2019.
[I-D.ietf-pce-sr-bidir-path]
Li, C., Chen, M., Cheng, W., Gandhi, R., and Q. Xiong,
"PCEP Extensions for Associated Bidirectional Segment
Routing (SR) Paths", draft-ietf-pce-sr-bidir-path-01 (work
in progress), February 2020.
Acknowledgments
The authors would like to thank Thierry Couture for the discussions
on the use-cases for TWAMP Light in Segment Routing. The authors
would also like to thank Greg Mirsky for reviewing this document and
providing useful comments and suggestions. Patrick Khordoc and Radu
Valceanu, both from Cisco Systems have helped significantly improve
the mechanisms defined in this document. The authors would like to
acknowledge the earlier work on the loss measurement using TWAMP
described in draft-xiao-ippm-twamp-ext-direct-loss. The authors
would also like to thank Sam Aldrin for the discussions to check for
broken path.
Authors' Addresses
Gandhi, et al. Expires September 2, 2020 [Page 32]
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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 September 2, 2020 [Page 33]