Internet DRAFT - draft-chen-ospf-source-label-distribution
draft-chen-ospf-source-label-distribution
Network Working Group M. Chen
Internet-Draft Huawei
Intended status: Standards Track G. Mirsky
Expires: August 17, 2014 Ericsson
February 13, 2014
Extensions to OSPF for Source Label Distribution
draft-chen-ospf-source-label-distribution-00
Abstract
An MPLS Source Label (SL) is defined to identify a node that is (one
of) the ingress LSRs to a specific LSP. This document defines
extensions to OSPF protocol for distribution of the mapping of an
MPLS Source Label to an specific LSR. Therefore, the egress and
intermediate LSRs can determine from which LSR an MPLS packet is
sent.
This document also defines OSPF extensions to advertise the Source
Label Capability (SLC) of each LSR that indicates whether an LSR can
process the Source Label. With the SLC, an ingress LSR can determine
whether it is allowed to insert a Source Label into the label stack
for a specific LSP.
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].
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
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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 17, 2014.
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Copyright Notice
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Extensions to OSPF . . . . . . . . . . . . . . . . . . . . . 3
3. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
7.1. Normative References . . . . . . . . . . . . . . . . . . 4
7.2. Informative References . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
The MPLS Source Label is defined in [I-D.chen-mpls-source-label], it
is used to identify (one of) the ingress LSR(s) of an LSP. To
identify from where an MPLS packet is sent, a pure Source Label (SL)
is not enough, it needs to know to which LSR a SL is correlated.
Therefore, there needs a mechanism to distribute the mapping
information between a SL and its correlated LSR.
In addition, for an ingress LSR, before inserting a SL in the label
stack of an LSP, it needs to know whether the egress LSR has the
capability to process the SL, otherwise the packet will be dropped at
the egress LSR. The capability is called Source Label Capability
(SLC).
This document defines extensions to OSPF protocol to distribute SL to
LSR mapping and advertise the SLC of each LSR.
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2. Extensions to OSPF
The Source Label TLV is defined to distribute the Source Label to
ingress LSR mapping information and the SLC. No sub-TLV is currently
defined for the Source Label TLV.
The Source Label TLV is advertised in an OSPF Router Information (RI)
[RFC4790] Link State Advertisement (LSA), it 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Router ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Source Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 - OSPF Source Label TLV format
The value of Type field is TBD1.
The Length field defines the length of the Reserved and Source Label
in octets, the value is 4.
The Source Label field contains the Source Label that identifies the
advertising LSR.
3. Elements of Procedure
The Source Label TLV is carried in the OSPF Router Information (RI)
LSAs that is defined in [RFC4790]. All the procedures that defined
in [RFC4790] are inherited here.
The flooding scope of the Source Label TLV can be either area local
or entire OSPF domain. The flooding scope is controlled by the
Opaque LSA type in OSPFv2 [RFC2370] and by the S1 and S2 bits in
OSPFv3 [RFC2740]. If the flooding scope is area local, the Source
Label TLV MUST be carried within an OSPFv2 Type 10 RI LSA or within
an OSPFv3 RI LSA with the S1 bit set and the S2 bit clear. If the
flooding scope is the entire IGP domain, the Source Label TLV MUST be
carried within an OSPFv2 Type 11 RI LSA or within an OSPFv3 RI LSA
with the S1 bit clear and the S2 bit set.
The Source Label TLV is an optional TLV. Upon receipt the TLV, a
router will silently ignore the TLV as defined in [RFC4790] if it
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does not support it. If Source Label TLV is not present that MUST be
interpreted as signaling of non-support of SLC by the LSR. Presence
of a Source Label TLV MUST be interpreted as support of SLC by the
LSR. A Source Label TLV MUST appear only one time in an LSA.
4. IANA Considerations
IANA is requested to assign a new TLV code point for the Source Label
TLV carried within the Router Information LSA.
Type Value TLV Name Reference
---------- --------------- --------------
TBD1 Source Label (this document)
5. Security Considerations
TBD.
6. Acknowledgements
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2370] Coltun, R., "The OSPF Opaque LSA Option", RFC 2370, July
1998.
[RFC2740] Coltun, R., Ferguson, D., and J. Moy, "OSPF for IPv6", RFC
2740, December 1999.
[RFC4790] Newman, C., Duerst, M., and A. Gulbrandsen, "Internet
Application Protocol Collation Registry", RFC 4790, March
2007.
7.2. Informative References
[I-D.chen-mpls-source-label]
Chen, M., Building, K., Li, Z., and L. Fang,
"MultiProtocol Label Switching (MPLS) Source Label",
draft-chen-mpls-source-label-01 (work in progress),
October 2013.
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Authors' Addresses
Mach(Guoyi) Chen
Huawei
Email: mach.chen@huawei.com
Greg Mirsky
Ericsson
Email: Gregory.mirsky@ericsson.com
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