Internet DRAFT - draft-mirsky-mpls-oam-mpls-sr-ip
draft-mirsky-mpls-oam-mpls-sr-ip
MPLS Working Group G. Mirsky
Internet-Draft ZTE Corp.
Intended status: Standards Track October 22, 2019
Expires: April 24, 2020
Operations, Administration, and Maintenance for MPLS-SR over IP
draft-mirsky-mpls-oam-mpls-sr-ip-03
Abstract
Segment routing uses source routing paradigm to traffic engineering
by specifying segments a packet traverses through the network. MPLS
Segment Routing applies that paradigm to an MPLS data plane-based
networks. SR-MPLS over IP uses MPLS label stack as a source routing
instruction set and uses IP encapsulation/tunneling such as MPLS-in-
UDP as defined in RFC 7510 to realize a source routing mechanism
across MPLS, IPv4, and IPv6 data planes. This document describes
Operations, Administration, and Maintenance operations in SR-MPLS
over IP environment.
Status of This Memo
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This Internet-Draft will expire on April 24, 2020.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 2
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3
3. OAM in SR-MPLS over IP . . . . . . . . . . . . . . . . . . . 3
3.1. Fault Management OAM in SR-MPLS over IP . . . . . . . . . 3
3.2. Performance Monitoring OAM in SR-MPLS over IP . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5.1. Source MEP ID IP Address Type . . . . . . . . . . . . . . 4
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
7. Normative References . . . . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
Segment routing [RFC8402] uses source routing paradigm to traffic
engineering by specifying segments a packet traverses through the
network. MPLS Segment Routing (SR-MPLS)
[I-D.ietf-spring-segment-routing-mpls] applies that paradigm to an
MPLS data plane-based networks. SR-MPLS over IP uses MPLS label
stack as a source routing instruction set and uses IP encapsulation/
tunneling such as MPLS-in-UDP as defined in [RFC7510] to realize a
source routing mechanism across MPLS, IPv4, and IPv6 data planes.
This document describes Operations, Administration, and Maintenance
(OAM) operations in SR-MPLS over IP environment.
2. Conventions used in this document
2.1. Terminology
MPLS: Multiprotocol Label Switching
LSP: Label Switched Path
BFD: Bidirectional Forwarding Detection
SR Segment Routing
SR-MPLS Segment Routing in MPLS data plane
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FEC: Forwarding Equivalence Class
G-ACh: Generic Associated Channel
ACH: Associated Channel Header
GAL: G-ACh Label
OAM Operations, Administration, and Maintenance
2.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. OAM in SR-MPLS over IP
OAM operations support Fault Management and Performance Monitoring
components of FCAPS framework for network management. To achieve its
objectives, Fault Management OAM includes proactive and on-demand
protocols to provide constant monitoring of the network to detect the
failure in combination with on-demand tools to efficiently localize
and characterize the defect. Performance Monitoring OAM protocols
support measurement of packet loss and packet delay that enables
calculation of performance metrics, e.g., packet loss ration, inter-
packet delay variation, that are useful in monitoring the quality of
service in the network, detect and quantify the service degradation.
3.1. Fault Management OAM in SR-MPLS over IP
Fault management OAM toolset includes protocols to perform on-demand
failure detection and localization as well as proactively monitor
path continuity. An example of the former is echo request/reply,
e.g., Label Switched Path (LSP) Ping [RFC8029]. An example of the
latter - Bidirectional Forwarding Detection (BFD) over MPLS LSP
[RFC5884]. For SR-MPLS environment applicability and use of these
OAM tools defined in [RFC8287] and [I-D.mirsky-spring-bfd]
respectively. Both LSP Ping and BFD can be used either with IP/UDP
encapsulation or in Generic Associated Channel (G-ACh) [RFC5586].
The use of IP/UDP encapsulation is well-understood and has been
defined in [RFC8029]:
The IP header is set as follows: the source IP address is a
routable address of the sender; the destination IP address is a
(randomly chosen) IPv4 address from the range 127/8 or an IPv6
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address from the range 0:0:0:0:0:FFFF:7F00:0/104. The IP TTL is
set to 1. The source UDP port is chosen by the sender.
Using the sender's routable address enables the receiver to send an
echo reply or BFD control packets over the IP network. In some
environments, the overhead of extra IP/UDP encapsulations may be
considered as overburden and make to use more compact G-ACh
encapsulation instead. In such a case, the OAM control packet MUST
be immediately followed by the IP Address TLV
[I-D.mirsky-mpls-p2mp-bfd] with its Value field containing one of the
routable IP addresses of the sender.
3.2. Performance Monitoring OAM in SR-MPLS over IP
Performance monitoring in SR-MPLS over IP may be performed using
mechanisms defined in [RFC6374]. Unlike FM OAM protocols for MPLS,
[RFC6374] does not define the use of IP encapsulation. Instead, the
addressing object of the type Return Address MUST be used in two-way
measurements or queries.
4. Security Considerations
This document does not introduce new security aspects but inherits
all security considerations from [RFC8287], [RFC8029], [RFC5884],
[I-D.mirsky-spring-bfd].
5. IANA Considerations
5.1. Source MEP ID IP Address Type
TBD.
6. Acknowledgements
TBD
7. Normative References
[I-D.ietf-spring-segment-routing-mpls]
Bashandy, A., Filsfils, C., Previdi, S., Decraene, B.,
Litkowski, S., and R. Shakir, "Segment Routing with MPLS
data plane", draft-ietf-spring-segment-routing-mpls-22
(work in progress), May 2019.
[I-D.mirsky-mpls-p2mp-bfd]
Mirsky, G., "BFD for Multipoint Networks over Point-to-
Multi-Point MPLS LSP", draft-mirsky-mpls-p2mp-bfd-07 (work
in progress), June 2019.
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[I-D.mirsky-spring-bfd]
Mirsky, G., Tantsura, J., Varlashkin, I., and M. Chen,
"Bidirectional Forwarding Detection (BFD) in Segment
Routing Networks Using MPLS Dataplane", draft-mirsky-
spring-bfd-08 (work in progress), August 2019.
[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>.
[RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed.,
"MPLS Generic Associated Channel", RFC 5586,
DOI 10.17487/RFC5586, June 2009,
<https://www.rfc-editor.org/info/rfc5586>.
[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>.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374,
DOI 10.17487/RFC6374, September 2011,
<https://www.rfc-editor.org/info/rfc6374>.
[RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black,
"Encapsulating MPLS in UDP", RFC 7510,
DOI 10.17487/RFC7510, April 2015,
<https://www.rfc-editor.org/info/rfc7510>.
[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>.
[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>.
[RFC8287] Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya,
N., Kini, S., and M. Chen, "Label Switched Path (LSP)
Ping/Traceroute for Segment Routing (SR) IGP-Prefix and
IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data
Planes", RFC 8287, DOI 10.17487/RFC8287, December 2017,
<https://www.rfc-editor.org/info/rfc8287>.
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[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>.
Author's Address
Greg Mirsky
ZTE Corp.
Email: gregimirsky@gmail.com
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