Network Working Group K. Kompella (Juniper Networks)
Internet Draft Y. Rekhter (Juniper Networks)
Expiration Date: November 2002 A. Banerjee (Calient Networks)
J. Drake (Calient Networks)
G. Bernstein (Ciena)
D. Fedyk (Nortel Networks)
E. Mannie (GTS Network)
D. Saha (Tellium)
V. Sharma (Metanoia, Inc.)
IS-IS Extensions in Support of Generalized MPLS
draft-ietf-isis-gmpls-extensions-11.txt
1. Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
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and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as ``work in progress.''
The list of current Internet-Drafts can be accessed at
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2. Abstract
This document specifies encoding of extensions to the IS-IS routing
protocol in support of Generalized Multi-Protocol Label Switching.
3. Summary for Sub-IP Area
3.1. Summary
This document specifies encoding of extensions to the IS-IS routing
protocol in support of Generalized Multi-Protocol Label Switching
(GMPLS). The description of the extensions is specified in [GMPLS-
ROUTING].
3.2. Where does it fit in the Picture of the Sub-IP Work
This work fits squarely in either CCAMP or IS-IS boxes.
3.3. Why is it Targeted at this WG
This draft is targeted at either the CCAMP or IS-IS WGs, because this
draft specifies the extensions to the IS-IS routing protocols in
support of GMPLS, because GMPLS is within the scope of CCAMP WG, and
because IS-IS is within the scope of the IS-IS WG.
3.4. Justification
The WG should consider this document as it specifies the extensions
to the IS-IS routing protocols in support of GMPLS.
4. Specification of Requirements
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].
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5. Introduction
This document specifies extensions to the IS-IS routing protocol in
support of carrying link state information for Generalized Multi-
Protocol Label Switching (GMPLS). The set of required enhancements to
IS-IS are outlined in [GMPLS-ROUTING].
6. IS-IS Routing Enhancements
In this section we define the enhancements to the TE properties of
GMPLS TE links that can be announced in IS-IS TE LSAs.
In this document, we enhance the sub-TLVs for the extended IS
reachability TLV (see [ISIS-TE]) in support of GMPLS. Specifically,
we add the following sub-TLVs:
Sub-TLV Type Length Name
4 4 Link Local/Remote Identifiers
20 2 Link Protection Type
21 variable Interface Switching Capability Descriptor
We further add one new TLV to the TE LSAs.
TLV Type Length Name
138 variable Shared Risk Link Group
6.1. Link Local/Remote Identifiers
A Link Local Interface Identifiers is a sub-TLV of the extended IS
reachability TLV. The type of this sub-TLV is 4, and length is eight
octets. The value field of this sub-TLV contains four octets of Link
Local Identifier followed by four octets of Link Remote Idenfier (see
Section "Support for unnumbered links" of [GMPLS-ROUTING]). If the
Link Remote Identifier is unknown, it is set to 0.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Idenfiier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Remote Idenfiier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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6.2. Link Protection Type
The Link Protection Type is is a sub-TLV (of type 20) of the
extended IS reachability TLV, with length two octets.
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Protection Cap | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The first octet is a bit vector describing the protection
capabilities of the link (see Section "Link Protection Type" of
[GMPLS-ROUTING]). They are:
0x01 Extra Traffic
0x02 Unprotected
0x04 Shared
0x08 Dedicated 1:1
0x10 Dedicated 1+1
0x20 Enhanced
0x40 Reserved
0x80 Reserved
The second octet SHOULD be set to zero by the sender, and SHOULD be
ignored by the receiver.
The Link Protection Type sub-TLV may occur at most once within the
extended IS reachability TLV.
6.3. Interface Switching Capability Descriptor
The Interface Switching Capability Descriptor is a sub-TLV (of type
21) of the extended IS reachability TLV. The length is the length of
value field in octets. The format of the value field is as shown
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Switching Cap | Encoding | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 7 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switching Capability-specific information |
| (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Switching Capability (Switching Cap) field contains one of the
following values:
1 Packet-Switch Capable-1 (PSC-1)
2 Packet-Switch Capable-2 (PSC-2)
3 Packet-Switch Capable-3 (PSC-3)
4 Packet-Switch Capable-4 (PSC-4)
51 Layer-2 Switch Capable (L2SC)
100 Time-Division-Multiplex Capable (TDM)
150 Lambda-Switch Capable (LSC)
200 Fiber-Switch Capable (FSC)
The Encoding field contains one of the values specified in Section
3.1.1 of [GMPLS-SIG].
Maximum LSP Bandwidth is encoded as a list of eight 4 octet fields in
the IEEE floating point format, with priority 0 first and priority 7
last. The units are bytes (not bits!) per second.
The content of the Switching Capability specific information field
depends on the value of the Switching Capability field.
When the Switching Capability field is PSC-1, PSC-2, PSC-3, or PSC-4,
the Switching Capability specific information field includes Minimum
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LSP Bandwidth and Interface MTU.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum LSP Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Minimum LSP Bandwidth is is encoded in a 4 octets field in the
IEEE floating point format. The units are bytes (not bits!) per
second. The Interface MTU is encoded as a 2 octets integer.
When the Switching Capability field is L2SC, there is no Switching
Capability specific information field present.
When the Switching Capability field is TDM, the Switching Capability
specific information field includes Minimum LSP Bandwidth and an
indication whether the interface supports Standard or Arbitrary
SONET/SDH.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum LSP Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Indication |
+-+-+-+-+-+-+-+-+
The Minimum LSP Bandwidth is encoded in a 4 octets field in the IEEE
floating point format. The units are bytes (not bits!) per second.
The indication whether the interface supports Standard or Arbitrary
SONET/SDH is encoded as 1 octet. The value of this octet is 0 if the
interface supports Standard SONET/SDH, and 1 if the interface
supports Arbitrary SONET/SDH.
When the Switching Capability field is LSC, there is no Switching
Capability specific information field present.
To support interfaces that have more than one Interface Switching
Capability Descriptor (see Section "Interface Switching Capability
Descriptor" of [GMPLS-ROUTING]) the Interface Switching Capability
Descriptor sub-TLV may occur more than once within the extended IS
reachability TLV.
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6.4. Shared Risk Link Group TLV
The SRLG TLV (of type 138 TBD) contains a data structure consisting
of:
7 octets of System ID and Pseudonode Number
1 octet Flag
4 octets of IPv4 interface address or 4 octets of a Link Local
Identifier
4 octets of IPv4 neighbor address or 4 octets of a Link Remote
Identifier
and a list of SRLG values, where each element in the list has 4
octets. The length of this TLV is 16 + 4 * (number of SRLG values).
The Least Significant Bit of the Flag octet indicates whether the
interface is numbered (set to 1), or unnumbered (set to 0). All other
bits are reserved and should be set to 0.
The neighbor is identified by its System Id (6-octets), plus one
octet to indicate the pseudonode number if the neighbor is on a LAN
interface.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| System ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| System ID (cont.) | Pseudonode num|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Shared Risk Link Group Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ............ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Shared Risk Link Group Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV carries the Shared Risk Link Group information (see Section
"Shared Risk Link Group Information" of [GMPLS-ROUTING]).
6.5. Link Identifier for Unnumbered Interfaces
Link Identifies are exchanged in the Extended Local Circuit ID field
of the "Point-to-Point Three-Way Adjacency" IS-IS Option type
[ISIS-3way].
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7. Implications on Graceful Restart
The restarting node should follow the ISIS restart procedures [ISIS-
RESTART], and the RSVP-TE restart procedures [GMPLS-RSVP].
When the restarting node is going to originate its TE LSAs, these
LSAs should be originated with 0 unreserved bandwidth, Traffic
Engineering Default metric set to MAX_PATH_METRIC, and if the Link
has LSC or FSC as its Switching Capability then also with 0 as Max
LSP Bandwidth, until the node is able to determine the amount of
unreserved resources taking into account the resources reserved by
the already established LSPs that have been preserved across the
restart. Once the restarting node determines the amount of unreserved
resources, taking into account the resources reserved by the already
established LSPs that have been preserved across the restart, the
node should advertise these resources in its TE LSAs.
In addition in the case of a planned restart prior to restarting, the
restarting node SHOULD originate the TE LSAs with 0 as unreserved
bandwidth, and if the Link has LSC or FSC as its Switching Capability
then also with 0 as Max LSP Bandwidth. This would discourage new LSP
establishment through the restarting router.
Neighbors of the restarting node should continue advertise the actual
unreserved bandwidth on the TE links from the neighbors to that node.
Regular graceful restart should not be aborted if a TE LSA or TE
topology changes. TE graceful restart need not be aborted if a TE LSA
or TE topology changes.
8. Security Considerations
The extensions proposed in this document does not raise any new
security concerns.
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9. Acknowledgements
The authors would like to thank Suresh Katukam, Jonathan Lang and
Quaizar Vohra for their comments on the draft.
10. References
[ISIS-TE] Smit, H., Li, T., "IS-IS Extensions for Traffic
Engineering",
draft-ietf-isis-traffic-03.txt (work in progress)
[GMPLS-SIG] Generalized MPLS Group, "Generalized MPLS - Signaling
Functional
Description", draft-ietf-mpls-generalized-signaling-04.txt (work
in progress)
[GMPLS-ROUTING] "Routing Extensions in Support of Generalized MPLS",
draft-many-ccamp-gmpls-routing-01.txt (work in progress)
[ISIS-3way] "Three-Way Handshake for IS-IS Point-to-Point
Adjacencies",
draft-ietf-isis-3way-05.txt (work in progress)
[ISIS-RESTART] "Restart signaling for ISIS", draft-ietf-isis-
restart-00.txt
(work in progress)
[GMPLS-RSVP] "Generalized MPLS Signaling - RSVP-TE Extensions",
draft-ietf-mpls-generalized-rsvp-te-06.txt (work in progress)
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
11. Authors' Information
Kireeti Kompella
Juniper Networks, Inc.
1194 N. Mathilda Ave
Sunnyvale, CA 94089
Email: kireeti@juniper.net
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Yakov Rekhter
Juniper Networks, Inc.
1194 N. Mathilda Ave
Sunnyvale, CA 94089
Email: yakov@juniper.net
Ayan Banerjee
Calient Networks
5853 Rue Ferrari
San Jose, CA 95138
Phone: +1.408.972.3645
Email: abanerjee@calient.net
John Drake
Calient Networks
5853 Rue Ferrari
San Jose, CA 95138
Phone: (408) 972-3720
Email: jdrake@calient.net
Greg Bernstein
Ciena Corporation
10480 Ridgeview Court
Cupertino, CA 94014
Phone: (408) 366-4713
Email: greg@ciena.com
Don Fedyk
Nortel Networks Corp.
600 Technology Park Drive
Billerica, MA 01821
Phone: +1-978-288-4506
Email: dwfedyk@nortelnetworks.com
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Eric Mannie
GTS Network Services
RDI Department, Core Network Technology Group
Terhulpsesteenweg, 6A
1560 Hoeilaart, Belgium
Phone: +32-2-658.56.52
E-mail: eric.mannie@gtsgroup.com
Debanjan Saha
Tellium Optical Systems
2 Crescent Place
P.O. Box 901
Ocean Port, NJ 07757
Phone: (732) 923-4264
Email: dsaha@tellium.com
Vishal Sharma
Metanoia, Inc.
335 Elan Village Lane, Unit 203
San Jose, CA 95134-2539
Phone: +1 408-943-1794
Email: v.sharma@ieee.org
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