CCAMP Working Group K. Kompella (Juniper Networks)
Internet Draft Y. Rekhter (Juniper Networks)
Expiration Date: October 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.)
OSPF Extensions in Support of Generalized MPLS
draft-ietf-ccamp-ospf-gmpls-extensions-06.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-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as ``work in progress.''
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
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2. Abstract
This document specifies encoding of extensions to the OSPF 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 OSPF 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 the CCAMP or OSPF box.
3.3. Why is it Targeted at this WG
This draft is targeted at the CCAMP or the OSPF WG, because this
draft specifies the extensions to the OSPF routing protocols in
support of GMPLS, because GMPLS is within the scope of the CCAMP WG,
and because OSPF is within the scope of the OSPF WG.
3.4. Justification
The WG should consider this document as it specifies the extensions
to the OSPF 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 OSPF routing protocol in
support of carrying link state information for Generalized Multi-
Protocol Label Switching (GMPLS). The set of required enhancements to
OSPF are outlined in [GMPLS-ROUTING].
6. OSPF Routing Enhancements
In this section we define the enhancements to the TE properties of
GMPLS TE links that can be announced in OSPF TE LSAs. The Traffic
Engineering (TE) LSA, which is an opaque LSA with area flooding scope
[OSPF-TE], has only one top-level Type/Length/Value (TLV) triplet and
has one or more nested sub-TLVs for extensibility. The top-level TLV
can take one of two values (1) Router Address or (2) Link. In this
document, we enhance the sub-TLVs for the Link TLV in support of
GMPLS. Specifically, we add the following sub-TLVs to the Link TLV:
Sub-TLV Type Length Name
11 8 Link Local/Remote Identifiers
14 4 Link Protection Type
15 variable Interface Switching Capability Descriptor
16 variable Shared Risk Link Group
6.1. Link Local/Remote Identifiers
A Link Local/Remote Identifiers is a sub-TLV of the Link TLV. The
type of this sub-TLV is 11, 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
A node can communicate its Link Local Identifier to its neighbor
using a link local Opaque LSA, as described in Section "Exchanging
Link Local TE Information".
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6.2. Link Protection Type
The Link Protection Type is a sub-TLV of the Link TLV. The type of
this sub-TLV is 14, and length is four octets.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|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 remaining three octets 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
Link TLV.
6.3. Shared Risk Link Group (SRLG)
The SRLG is a sub-TLV (of type 16) of the Link TLV. The length is the
length of the list in octets. The value is an unordered list of 32
bit numbers that are the SRLGs that the link belongs to. 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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| Shared Risk Link Group Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ............ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Shared Risk Link Group Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This sub-TLV carries the Shared Risk Link Group information (see
Section "Shared Risk Link Group Information" of [GMPLS-ROUTING]).
The SRLG sub-TLV may occur at most once within the Link TLV.
6.4. Interface Switching Capability Descriptor
The Interface Switching Capability Descriptor is a sub-TLV (of type
15) of the Link 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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:
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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
LSP Bandwidth, Interface MTU, and padding.
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 | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. The
padding is 2 octets, and is used to make the Interface Switching
Capability Descriptor sub-TLV 32-bits aligned. It SHOULD be set to
zero by the sender and SHOULD be ignored by the receiver.
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, an
indication whether the interface supports Standard or Arbitrary
SONET/SDH, and padding.
0 1 2 3
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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 | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. The padding is 3 octets, and is used
to make the Interface Switching Capability Descriptor sub-TLV 32-bits
aligned. It SHOULD be set to zero by the sender and SHOULD be ignored
by the receiver.
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 Link TLV.
7. Implications on Graceful Restart
The restarting node should follow the OSPF restart procedures [OSPF-
RESTART], and the RSVP-TE restart procedures [GMPLS-RSVP].
When a restarting node is going to originate its TE LSAs, the TE LSAs
containing Link TLV should be originated with 0 unreserved bandwidth,
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 containing Link TLV 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.
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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. Exchanging Link Local TE Information
It is often useful for a node to communicate some Traffic Engineering
information for a given interface to its neighbors on that interface.
One example of this is a Link Local Identifier. If nodes X and Y are
connected by an unnumbered point-to-point interface I, then X's Link
Local Identifier for I is Y's Link Remote Identifier for I. X can
communicate its Link Local Identifer for I by exchanging with Y a TE
link local opaque LSA described below. Note that this information
need only be exchanged over interface I, hence the use of a link
local Opaque LSA.
A TE Link Local LSA is an opaque LSA of type 9 (link-local flooding
scope) with Opaque Type [TBD] and Opaque ID of 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS age | Options | 9 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Opaque Type | Opaque ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Advertising Router |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS sequence number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS checksum | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+- TLVs -+
| ... |
The format of the TLVs that make up the body of the TE Link Local LSA
is the same as that of the TE TLVs: a 2-octet Type field followed by
a 2-octet Length field which indicates the length of the Value field
in octets. The Value field is zero-padded at the end to a four octet
boundary.
The only TLV defined here is the Link Local Identifier TLV, with Type
1, Length 4 and Value the 32 bit Link Local Identifier for the link
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over which the TE Link Local LSA is exchanged.
9. Security Considerations
The sub-TLVs proposed in this document do not raise any new security
concerns.
10. Acknowledgements
The authors would like to thank Suresh Katukam, Jonathan Lang,
Quaizar Vohra, and Alex Zinin for their comments on the draft.
11. References
[OSPF-TE] Katz, D., Yeung, D., "Traffic Engineering Extensions to
OSPF",
draft-katz-yeung-ospf-traffic-06.txt (work in progress)
[GMPLS-SIG] "Generalized MPLS - Signaling Functional
Description", draft-ietf-mpls-generalized-signaling-04.txt (work
in progress)
[GMPLS-RSVP] "Generalized MPLS Signaling - RSVP-TE Extensions",
draft-ietf-mpls-generalized-rsvp-te-06.txt (work in progress)
[GMPLS-ROUTING] "Routing Extensions in Support of Generalized MPLS",
draft-ietf-ccamp-gmpls-routing-01.txt (work in progress)
[OSPF-RESTART] "Hitless OSPF Restart", draft-ietf-ospf-hitless-
restart-02.txt
(work in progress)
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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12. 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
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
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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
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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