Network Working Group X. Xu
Internet-Draft Huawei
Intended status: Standards Track S. Kini
Expires: June 18, 2014 Ericsson
S. Sivabalan
C. Filsfils
Cisco
December 18, 2013
Signaling Entropy Label Capability Using OSPF
draft-xu-ospf-mpls-elc-00
Abstract
Multi Protocol Label Switching (MPLS) has defined a mechanism to load
balance traffic flows using Entropy Labels (EL). An ingress LSR
cannot insert ELs for packets going into a given tunnel unless an
egress LSR has indicated via signaling that it can process ELs on
that tunnel. This draft defines a mechanism to signal that
capability using OSPF. This mechanism is useful when the label
advertisement is also done via OSPF.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on June 18, 2014.
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Internet-Draft December 2013
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Advertising ELC using OSPF . . . . . . . . . . . . . . . . . 2
4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
6. Security Considerations . . . . . . . . . . . . . . . . . . . 3
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 3
7.1. Normative References . . . . . . . . . . . . . . . . . . 3
7.2. Informative References . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
Multi Protocol Label Switching (MPLS) has defined a method in
[RFC6790] to load balance traffic flows using Entropy Labels (EL).
An ingress LSR cannot insert ELs for packets going into a given
tunnel unless an egress LSR has indicated via signaling that it can
process ELs on that tunnel. [RFC6790] defines the signaling of this
capability (a.k.a Entropy Label Capability - ELC) via signaling
protocols. Recently, mechanisms are being defined to signal labels
via link state Interior Gateway Protocols (IGP) such as OSPF
[I-D.psenak-ospf-segment-routing-extensions] . In such scenario the
signaling mechanisms defined in [RFC6790] are inadequate. This draft
defines a mechanism to signal the ELC using OSPF. This mechanism is
useful when the label advertisement is also done via OSPF.
1.1. 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 RFC 2119 [RFC2119].
2. Terminology
This memo makes use of the terms defined in [RFC6790] and [RFC4970].
3. Advertising ELC using OSPF
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The OSPF Router Information (RI) Opaque LSA defined in [RFC4970] is
used by OSPF routers to announce their capabilities. A new TLV
within the body of this LSA, called ELC TLV is defined to advertise
the capability of the router to process the ELs. It is formatted as
described in sec 2.1 of [RFC4970]. This TLV is applicable to both
OSPFv2 and OSPFv3. The Type for the ELC TLV needs to be assigned by
IANA and it has a Length of zero. The scope of the advertisement
depends on the application but it is recommended that it SHOULD be
AS-scoped.
4. Acknowledgements
The authors would like to thank Yimin Shen and George Swallow for
their comments.
5. IANA Considerations
This memo includes a request to IANA to allocate a TLV type from the
OSPF RI TLVs registry.
6. Security Considerations
This document does not introduce any new security considerations.
7. References
7.1. Normative References
[I-D.psenak-ospf-segment-routing-extensions]
Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
Shakir, R., and W. Henderickx, "OSPF Extensions for
Segment Routing", draft-psenak-ospf-segment-routing-
extensions-03 (work in progress), October 2013.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4970] Lindem, A., Shen, N., Vasseur, JP., Aggarwal, R., and S.
Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 4970, July 2007.
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, October 2008.
[RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and
L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
RFC 6790, November 2012.
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7.2. Informative References
[I-D.filsfils-rtgwg-segment-routing]
Filsfils, C., Previdi, S., Bashandy, A., Decraene, B.,
Litkowski, S., Horneffer, M., Milojevic, I., Shakir, R.,
Ytti, S., Henderickx, W., Tantsura, J., and E. Crabbe,
"Segment Routing Architecture", draft-filsfils-rtgwg-
segment-routing-01 (work in progress), October 2013.
Authors' Addresses
Xiaohu Xu
Huawei
Email: xuxiaohu@huawei.com
Sriganesh Kini
Ericsson
Email: sriganesh.kini@ericsson.com
Siva Sivabalan
Cisco
Email: msiva@cisco.com
Clarence Filsfils
Cisco
Email: cfilsfil@cisco.com
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