Network Working Group K. Kompella (Juniper Networks)
Internet Draft Y. Rekhter (Juniper Networks)
Expiration Date: August 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-08.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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Internet Draft draft-ietf-isis-gmpls-extensions-08.txt February 2002
2. Abstract
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. 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.
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4. 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].
5. 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:
1. Link Local Identifier
2. Remote Interface Identifier
3. Link Protection Type
4. Interface Switching Capability Descriptor
This brings the list of sub-TLVs of the extended IS reachability TLV
to:
Sub-TLV Type Length Name
3 4 Administrative group (color)
4 4 Link Local Identifier
5 4 Link Remote Identifier
6 variable IPv4 interface address
8 variable IPv4 neighbor address
9 4 Maximum link bandwidth
10 4 Reservable link bandwidth
11 32 Unreserved bandwidth
18 3 TE Default metric
20 2 Link Protection Type
21 variable Interface Switching Capability Descriptor
250-254 - Reserved for cisco specific extensions
255 - Reserved for future expansion
We further add one new TLV to the TE LSAs.
TLV Type Length Name
138 (TBD) variable Shared Risk Link Group
Finally, we add one more TLV to the Hello PDUs.
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TLV Type Length Name
(TBD) 4 Link Identifier
5.1. Link Local Identifier
A Link Local Interface Identifier is a sub-TLV of the extended IS
reachability TLV with type 4, and length 4.
5.2. Link Remote Identifier
A Link Remote Identifier is a sub-TLV of the extended IS reachability
TLV with type 5, and length 4.
5.3. 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, the first of
which is a bit vector describing the protection capabilities of the
link. They are:
0x01 Extra Traffic
0x02 Unprotected
0x04 Shared
0x08 Dedicated 1:1
0x10 Dedicated 1+1
0x20 Enhanced
0x40 Reserved
0x80 Reserved
5.4. 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:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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
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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 specific information includes Interface MTU and Minimum LSP
Bandwidth. The Interface MTU is encoded as a 2 octets integer. 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.
When the Switching Capability field is L2SC, there is no specific
information.
When the Switching Capability field is TDM, the specific information
includes Minimum LSP Bandwidth, and an indication whether the
interface supports Standard or Arbitrary SONET/SDH. 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 specific
information.
The Interface Switching Capability Descriptor sub-TLV may occur more
than once within the extended IS reachability TLV (this is needed to
handle interfaces that support multiple switching capabilities).
5.5. Shared Risk Link Group TLV
The proposed SRLG (of type 138 TBD) contains a new 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.
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5.6. Link Identifier for Unnumbered Interfaces
The Link Identifier TLV is carried as part of the Point-to-point ISIS
Hello PDUs. The Type field of this TLV is TBD. The Length field of
this TLV is set to 4. The Value field of this TLV contains 4 octets
that encode the Identifier assigned to the link over which this PDU
is to be transmitted by the LSR that transmits the PDU.
6. Implications on Graceful Restart
The restarting node should follow the ISIS restart procedures [ISIS-
RESTART], and the RSVP-TE restart procedures [GMPLS-RSVP].
Once the restarting node re-establishes at least one ISIS adjacency,
the node should originate its TE LSAs. These LSAs should be
originated with 0 unreserved 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.
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.
7. Security Considerations
The extensions proposed in this document does not raise any new
security concerns.
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8. Acknowledgements
The authors would like to thank Suresh Katukam, Jonathan Lang and
Quaizar Vohra for their comments on the draft.
9. 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-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)
10. Authors' Information
Kireeti Kompella
Juniper Networks, Inc.
1194 N. Mathilda Ave
Sunnyvale, CA 94089
Email: kireeti@juniper.net
Yakov Rekhter
Juniper Networks, Inc.
1194 N. Mathilda Ave
Sunnyvale, CA 94089
Email: yakov@juniper.net
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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
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
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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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