Network Working Group Z. Li
Internet-Draft China Mobile
Intended status: Standards Track M. Chen
Expires: August 23, 2021 Huawei
G. Mirsky
ZTE Corp.
February 19, 2021
Simple Two-Way Active Measurement Protocol Extensions for Performance
Measurement on LAG
draft-li-ippm-stamp-on-lag-00
Abstract
This document defines extensions to Simple Two-Way Active Measurement
Protocol (STAMP) to implement performance measurement on every member
link of a Link Aggregation Group (LAG). Knowing the measured metrics
of each member link of a LAG enables operators to enforce a
performance metric-based traffic steering policy across the member
links.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC2119] [RFC8174] when, and only when, they appear in all capitals,
as shown here.
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
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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 August 23, 2021.
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Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Micro-Session on LAG . . . . . . . . . . . . . . . . . . . . 3
3. Micro-STAMP Session . . . . . . . . . . . . . . . . . . . . . 4
3.1. Micro-STAMP-Test . . . . . . . . . . . . . . . . . . . . 4
3.1.1. LAG Member Link ID TLV . . . . . . . . . . . . . . . 4
3.1.2. Micro-STAMP-Test Procedures . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Link Aggregation Group (LAG), as defined in [IEEE802.1AX], provides
mechanisms to combine multiple physical links into a single logical
link. This logical link offers higher bandwidth and better
resiliency, because if one of the physical member links fails, the
aggregate logical link can continue to forward traffic over the
remaining operational physical member links.
Usually, when forwarding traffic over a LAG, a hash-based or similar
mechanism is used to load-balance the traffic across the LAG member
links. In some cases, the link delays of the member links are
different because they are over different transport paths. To
provide low delay service to time-sensitive traffic, we have to know
the link delay of each member link of a LAG and then steer traffic
accordingly. That requires a solution that could measure the
performance metrics of each member link of a LAG.
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However, when using Simple Two-Way Active Measurement Protocol
(STAMP) [RFC8762] to measure a LAG's performance, the LAG is treated
as a single logical link/path. The measured metrics reflect the
performance of one member link or an average of some/all member links
of the LAG.
In addition, for LAG, using passive or hybrid methods (like
alternative marking[RFC8321] or iOAM [I-D.ietf-ippm-ioam-data]) can
only monitor the link crossed by traffic. It means that the measured
metrics reflect the performance of some member links or an average of
some/all member links of the LAG. Therefore, in order to measure
every link of a LAG, using active methods would be more appropriate.
This document defines extensions to STAMP [RFC8762] to implement
performance measurement on every member link of a LAG.
2. Micro-Session on LAG
This document intends to address the scenario (e.g., Figure 1) where
a LAG (e.g., the LAG includes three member links) directly connects
two nodes (A and B) . The goal is to measure the performance of each
link of the LAG.
+---+ +---+
| |-----------------------| |
| A |-----------------------| B |
| |-----------------------| |
+---+ +---+
Figure 1: PM for LAG
To measure performance metrics of every member link of a LAG,
multiple sessions (one session for each member link) need to be
established between the two hosts that are connected by the LAG.
These sessions are called micro-sessions for the remainder of this
document.
All micro-sessions of a LAG share the same Sender Address, Receiver
Address. As for the Sender Port and Receiver Port, the micro-
sessions may share the same Sender Port and Receiver Port pair, or
each micro session is configured with a different Sender Port and
Receiver Port pair. But from simplifying operation point of view,
the former is recommended.
In addition, with micro-sessions, there needs a way to correlate a
session with a member link. For example, when the Reflector receives
a Test packet, it needs to know from which member link the packet is
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received, and correlate it with a micro-session. That is a new
functionality for STAMP as defined in [RFC8762] and [RFC8972].
Upon receiving a Test packet for a micro-session, the receiver uses
the receiving link's identifier to correlate the packet to a
particular session. In addition, Test packets may need to carry the
member link information for validation checking. For example, when a
Session-Sender/Session-Reflector receives a Test packet, it may need
to check whether the Test packet is from the expected member link.
3. Micro-STAMP Session
3.1. Micro-STAMP-Test
The micro-STAMP-Test protocol is based on the STAMP-Test protocol
[RFC8762] and [RFC8972] with the following extensions.
3.1.1. LAG Member Link ID TLV
The LAG Member Link ID TLV is defined to carry the LAG member link
identifiers associated with a micro-STAMP session. The member link
identifiers are used for the Session-Sender and Session-Reflector to
check whether a Test packet is received from the expected member
link. The detailed procedures are defined in Section 3.1.2.
The format is as below:
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Member Link ID | Reflector Member Link ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: LAG Member Link ID TLV
Sender Member Link ID (2-octets in length): it is defined to carry
the LAG member link identifier of the Sender side. The value of the
Sender Member Link ID MUST be unique at the Session-Sender.
Reflector Member Link ID (2-octets in length): it is defined to carry
the LAG member link identifier of the Reflector side. The value of
the Reflector Member ID MUST be unique at the Session-Reflector.
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3.1.2. Micro-STAMP-Test Procedures
The micro-STAMP-Test reuses the procedures as defined in Section 4 of
STAMP [RFC8762] with the following additions:
The micro-STAMP Session-Sender MUST send the micro-STAMP-Test packets
over the member link associated with the session. The micro STAMP
Session-Reflector MUST send the reflected Test packets over the
receiving member link.
The configuration and management of the association between a micro-
STAMP session and the Sender/Reflector member link identifiers are
outside the scope of this document.
When the Session-Sender sends a Test packet, the LAG Member Link ID
TLV MUST be carried, and the Sender member link identifier associated
with the micro-STAMP session MUST be put in the Sender Member Link ID
field. If the Session-Sender knows the Reflector member link
identifier, it MUST set it as the Reflector Member Link ID field's
value. Otherwise, the Reflector Member Link ID field MUST be set to
zero.
The Session-Sender uses the Sender Member Link ID field's value to
check whether the reflected Test packet is received from the member
link associated with the correct micro-STAMP session. Therefore, the
Session-Reflector MUST copy the Sender Member Link ID value to the
reflected Test packet.
The Session-Reflector uses the Reflector Member Link ID value to
check whether a Test packet is received from the member link
associated with the correct micro-STAMP session.
The Reflector member link identifier can be obtained from pre-
configuration or learned through the data plane (e.g., learned from a
reflected Test packet). How to obtain/learn the Reflector member
link identifier is outside of this document's scope.
When the micro-STAMP Session-Reflector receives a Test packet, it
MUST use the receiving member link to correlate the Test packet to a
micro-STAMP session. If there is no such a micro-STAMP session, the
Test packet MUST be discarded. Suppose the Reflector Member Link ID
is not zero. In that case, the micro-STAMP Session-Reflector MUST
use the Reflector member link identifier to check whether it is
associated with the micro-STAMP session. If it is not, the Test
packet MUST be discarded and no reflected Test packet will be sent
back to the Session-Sender. If all validation passed, the Session-
Reflector sends a reflected Test packet to the Session-Sender over
the receiving member link. The micro-STAMP Session-Reflector MUST
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put the Sender and Reflector member link identifiers associated with
the micro-STAMP session in the Sender Member Link ID and Reflector
Member Link ID fields, respectively. The Sender member link
identifier is copied from the received Test packet.
When the micro-STAMP Session-Sender receives a reflected Test packet,
it MUST use the receiving member link to correlate the reflected Test
packet to a micro-STAMP session. If there is no such a session, the
reflected Test packet MUST be discarded. If a matched micro-STAMP
session exists, the Session-Sender MUST use the identifier carried in
the Sender Member Link ID field to check whether it associates with
the session. If the checking failed, the Test packet MUST be
discarded.
4. IANA Considerations
This document requires the IANA to allocate the following the TLV
type from the "STAMP TLV Types" sub-registry.
Value |Description | Reference
---------+----------------------+----------------------
TBD1 |LAG Member Link ID | This document
5. Security Considerations
This document does not introduce additional security requirements and
mechanisms other than the ones described in [RFC8762] apply to this
document.
6. Acknowledgements
The authors would like to thank Min Xiao, Fang Xin for the valuable
comments to this work.
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>.
7.2. Informative References
[I-D.ietf-ippm-ioam-data]
Brockners, F., Bhandari, S., and T. Mizrahi, "Data Fields
for In-situ OAM", draft-ietf-ippm-ioam-data-11 (work in
progress), November 2020.
[IEEE802.1AX]
IEEE Std. 802.1AX, "IEEE Standard for Local and
metropolitan area networks - Link Aggregation", November
2008.
[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>.
Authors' Addresses
Zhenqiang Li
China Mobile
Email: li_zhenqiang@hotmail.com
Mach(Guoyi) Chen
Huawei
Email: mach.chen@huawei.com
Greg Mirsky
ZTE Corp.
Email: gregimirsky@gmail.com
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