< draft-srisuresh-ospf-te-02.txt   draft-srisuresh-ospf-te-03.txt >
Network Working Group P. Srisuresh Network Working Group P. Srisuresh
INTERNET-DRAFT Kuokoa Networks INTERNET-DRAFT Kuokoa Networks
Expires as of July 04, 2002 P. Joseph Expires as of March 16, 2003 P. Joseph
Vivace Networks Force10 Networks
January 4, 2002 September 16, 2002
TE LSAs to extend OSPF for Traffic Engineering TE LSAs to extend OSPF for Traffic Engineering
<draft-srisuresh-ospf-te-02.txt> <draft-srisuresh-ospf-te-03.txt>
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
skipping to change at page 3, line 13 skipping to change at page 3, line 13
8.4. The Backup Designated Router ..........................19 8.4. The Backup Designated Router ..........................19
8.5. The graph of adjacencies ..............................19 8.5. The graph of adjacencies ..............................19
9. TE LSAs ....................................................20 9. TE LSAs ....................................................20
9.1. TE-Router LSA (0x81) ..................................22 9.1. TE-Router LSA (0x81) ..................................22
9.1.1. Router-TE flags - TE capabilities of the router.24 9.1.1. Router-TE flags - TE capabilities of the router.24
9.1.2. Router-TE TLVs .................................25 9.1.2. Router-TE TLVs .................................25
9.1.3. Link-TE options - TE capabilities of a TE-link .26 9.1.3. Link-TE options - TE capabilities of a TE-link .26
9.1.4. Link-TE TLVs ...................................26 9.1.4. Link-TE TLVs ...................................26
9.2. TE-incremental-link-Update LSA (0x8d) .................27 9.2. TE-incremental-link-Update LSA (0x8d) .................27
9.3. TE-Circuit-paths LSA (0x8C) ...........................29 9.3. TE-Circuit-paths LSA (0x8C) ...........................29
9.4. TE-Summary LSAs .......................................30 9.4. TE-Summary LSAs .......................................31
9.4.1. TE-Summary Network LSA (0x83) ..................30 9.4.1. TE-Summary Network LSA (0x83) ..................31
9.4.2. TE-Summary router LSA (0x84) ...................31 9.4.2. TE-Summary router LSA (0x84) ...................32
9.5. TE-AS-external LSAs (0x85) ............................33 9.5. TE-AS-external LSAs (0x85) ............................34
9.6. Changes to Network LSA ................................34 9.6. Changes to Network LSA ................................35
9.6.1. Positional-Ring type network LSA ...............34 9.6.1. Positional-Ring type network LSA ...............36
9.7. TE-Router-Proxy LSA (0x8e) ............................35 9.7. TE-Router-Proxy LSA (0x8e) ............................36
9.8. Others ................................................36 9.8. Others ................................................37
10. Abstract topology representation with TE support ...........36 10. Abstract topology representation with TE support ...........37
11. Changes to Data structures in OSPF-TE routers ..............38 11. Changes to Data structures in OSPF-TE routers ..............39
11.1. Changes to Router data structure .....................38 11.1. Changes to Router data structure .....................39
11.2. Two set of Neighbors .................................38 11.2. Two set of Neighbors .................................39
11.3. Changes to Interface data structure ..................38 11.3. Changes to Interface data structure ..................39
12. IANA Considerations ........................................39 12. IANA Considerations ........................................40
12.1. TE-compliant-SPF routers Multicast address allocation 39 12.1. TE-compliant-SPF routers Multicast address allocation 40
12.2. New TE-LSA Types .....................................39 12.2. New TE-LSA Types .....................................40
12.3. New TLVs (Router-TE and Link-TE TLVs) ................39 12.3. New TLVs (Router-TE and Link-TE TLVs) ................40
12.3.1. TE-selection-Criteria TLV (Tag ID = 1) .......39 12.3.1. TE-selection-Criteria TLV (Tag ID = 1) .......40
12.3.2. MPLS-Signaling protocol TLV (Tag ID = 3) .....39 12.3.2. MPLS-Signaling protocol TLV (Tag ID = 3) .....40
12.3.3. Constraint-SPF algorithms-Support TLV (Tag ID=4) 12.3.3. Constraint-SPF algorithms-Support TLV (Tag ID=4)
12.3.4. SRLG-TLV (Tag ID = 0x81) .....................39 12.3.4. SRLG-TLV (Tag ID = 0x81) .....................40
12.3.5. BW-TLV (Tag ID = 0x82) .......................40 12.3.5. BW-TLV (Tag ID = 0x82) .......................41
12.3.6. CO-TLV (Tag ID = ox83) .......................40 12.3.6. CO-TLV (Tag ID = ox83) .......................41
13. Acknowledgements ...........................................40 13. Acknowledgements ...........................................41
14. Security Considerations ....................................40 14. Security Considerations ....................................41
References .....................................................40 References .....................................................41
1. Introduction 1. Introduction
There is substantial industry experience with deploying OSPF link There is substantial industry experience with deploying OSPF link
state routing protocol. That makes OSPF a good candidate to adapt state routing protocol. That makes OSPF a good candidate to adapt
for traffic engineering purposes. The dynamic discovery of network for traffic engineering purposes. The dynamic discovery of network
topology, link access metrics, flooding algorithm and the topology, link access metrics, flooding algorithm and the
hierarchical organization of areas can all be used effectively in hierarchical organization of areas can all be used effectively in
creating and tearing traffic links on demand. The intent of creating and tearing traffic links on demand. The intent of
OSPF-TE is to discover TE network topology and the TE metrics OSPF-TE is to discover TE network topology and the TE metrics
skipping to change at page 21, line 41 skipping to change at page 21, line 41
summary LSAs, the TE-summary LSAs do not reveal the topological summary LSAs, the TE-summary LSAs do not reveal the topological
details of an area to external areas. But, the two summary LSAs details of an area to external areas. But, the two summary LSAs
do differ in some respects. The flooding scope of TE summary do differ in some respects. The flooding scope of TE summary
LSAs is different. As for content, TE summary network LSAs LSAs is different. As for content, TE summary network LSAs
simply describe reachability without summarization of network simply describe reachability without summarization of network
access costs. And, unlike the native summary router LSA, access costs. And, unlike the native summary router LSA,
TE-summary router LSA content includes TE capabilities of the TE-summary router LSA content includes TE capabilities of the
advertising TE router. advertising TE router.
TE-AS-external LSA and TE-Circuit-Path LSA are defined to TE-AS-external LSA and TE-Circuit-Path LSA are defined to
advertise AS external network reachability and pre-engineered advertise AS external network reachability and pre-established
TE circuits respectively. While flooding scope for both TE circuits respectively. While flooding scope for both
these LSAs can be the TE-topology in the entire AS, flooding these LSAs can be the TE-topology in the entire AS, flooding
scope for the pre-engineered TE circuit LSA may optionally be scope for the pre-established TE circuit LSA may optionally be
restricted to just the TE topology within an area. restricted to just the TE topology within an area.
Lastly, the new TE LSAs are defined so as to permit peer Lastly, the new TE LSAs are defined so as to permit peer
operation of packet networks and non-packet networks alike. operation of packet networks and non-packet networks alike.
As such, a new TE-Router-Proxy LSA is defined to allow As such, a new TE-Router-Proxy LSA is defined to allow
advertisement of a TE router, that is not OSPF capable, by advertisement of a TE router, that is not OSPF capable, by
an OSPF-TE node as a proxy. an OSPF-TE node as a proxy.
9.1. TE-Router LSA (0x81) 9.1. TE-Router LSA (0x81)
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the LSA and replace LSAs of the same tuple with an older sequence the LSA and replace LSAs of the same tuple with an older sequence
number. However, there is an exception to this rule in the context number. However, there is an exception to this rule in the context
of TE-link-update LSA. TE-Link update LSA will initially assume the of TE-link-update LSA. TE-Link update LSA will initially assume the
sequence number of the TE-router LSA it belongs to. Further, when a sequence number of the TE-router LSA it belongs to. Further, when a
new TE-router LSA update with a larger sequence number is advertised, new TE-router LSA update with a larger sequence number is advertised,
the newer sequence number is assumed by al the link LSAs. the newer sequence number is assumed by al the link LSAs.
9.3. TE-Circuit-paths LSA (0x8C) 9.3. TE-Circuit-paths LSA (0x8C)
TE-Circuit-paths LSA may be used to advertise the availability of TE-Circuit-paths LSA may be used to advertise the availability of
pre-engineered TE circuit path(s) originating from any router in pre-established TE circuit path(s) originating from any router
the network. The flooding scope may be Area wide or AS wide. in the network. The flooding scope may be Area wide or AS wide.
0 1 2 3 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 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 | 0x84 | | LS age | Options | 0x84 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link State ID | | Link State ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Advertising Router | | Advertising Router |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS sequence number | | LS sequence number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS checksum | length | | LS checksum | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0 |S|E|B| 0 | # of TE circuit paths | | 0 |G|E|B|D|S|T|CktType| Circuit Duration (Optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE-Link ID | | Circuit Duration cont... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE-Link Data | | Circuit Duartion cont.. | Circuit Setup time (Optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | 0 | Link-TE flags | | Circuit Setup time cont... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link-TE flags (contd.) | Zero or more Link-TE TLVs | | Circuit Setup time cont.. |Circuit Teardown time(Optional)|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE-Link ID | | Circuit Teardown time cont... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE-Link Data | | Circuit Teardown time cont.. | No. of TE circuit paths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Circuit-TE ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Circuit-TE Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | 0 | Circuit-TE flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Circuit-TE flags (contd.) | Zero or more Circuit-TE TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Circuit-TE ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Circuit-TE Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | | ... |
Link State ID Link State ID
The ID of the router to which the TE circuit path(s) is being The ID of the far-end router or the far-end Link-ID to which the
advertised. TE circuit path(s) is being advertised.
TE-circuit-path(s) flags TE-circuit-path(s) flags
Bit S - When set, the flooding scope is set to be AS wide. Bit G - When set, the flooding scope is set to be AS wide.
Otherwise, the flooding scope is set to be area wide. Otherwise, the flooding scope is set to be area wide.
Bit E - When set, the advertised Link-State ID is an AS boundary Bit E - When set, the advertised Link-State ID is an AS boundary
router (E is for external). The advertising router and router (E is for external). The advertising router and
the Link State ID belong to the same area. the Link State ID belong to the same area.
Bit B - When set, the advertised Link state ID is an Area border Bit B - When set, the advertised Link state ID is an Area border
router (B is for Border) router (B is for Border)
No. of Virtual TE Links Bit D - When set, this indicates that the duration of circuit
This indicates the number of pre-engineered TE links between the path validity follows.
advertising router and the router specified in the link state ID.
TE-Link ID Bit S - When set, this indicates that Setup-time of the circuit
This is the ID by which to identify the virtual link on the path follows.
advertising router. This can be any private interface index or
handle that the advertising router uses to identify the
pre-engineered TE virtual link to the ABR/ASBR.
TE-Link Data Bit T - When set, this indicates that teardown-time of the
This specifies the IP address of the physical interface circuit path follows.
on the advertising router.
CktType
This 4-bit field specifies the Circuit type of the Forward
Equivalency Class (FC).
0x01 - Origin is Router, Destination is Router.
0x02 - Origin is Link, Destination is Link.
0x04 - Origin is Router, Destination is Link.
0x08 - Origin is Link, Destination is Router.
Circuit Duration (Optional)
This 64-bit number specifies the seconds from the time of the
LSA advertisement for which the adversited pre-established
TE circuit path will be valid. This field is specified only
when the D-bit is set in the TE-circuit-path flags.
Circuit Setup time (Optional)
This 64-bit number specifies the time at which the TE-circuit
path may be setup. This field is specified only when the
S-bit is set in the TE-circuit-path flags. The setup time is
specified as the number of seconds from the start of January
1 1970 UTC.
Circuit Teardown time (Optional)
This 64-bit number specifies the time at which the TE-circuit
path may be torn down. This field is specified only when the
T-bit is set in the TE-circuit-path flags. The teardown time
is specified as the number of seconds from the start of
January 1 1970 UTC.
No. of TE Circuit paths
This indicates the number of pre-established TE circuit paths
between the advertising router and the router specified in the
link state ID.
Circuit-TE ID
This is the ID of the far-end router for a given TE-circuit
path segment.
Circuit-TE Data
This is the virtual link identifier on the near-end router for
a given TE-circuit path segment. This can be a private
interface or handle the near-end router uses to identify the
virtual link.
The sequence of (circuit-TE ID, Circuit-TE Data) list the
end-point nodes and links in the LSA as a series.
Circuit-TE flags
This lists the Zero or more TE-link TLVs that all member
elements of the LSP meet.
9.4. TE-Summary LSAs 9.4. TE-Summary LSAs
TE-Summary-LSAs are the Type 0x83 and 0x84 LSAs. These LSAs are TE-Summary-LSAs are the Type 0x83 and 0x84 LSAs. These LSAs are
originated by area border routers. TE-Summary-network-LSA (0x83) originated by area border routers. TE-Summary-network-LSA (0x83)
describes the reachability of TE networks in a non-backbone describes the reachability of TE networks in a non-backbone
area, advertised by the Area Border Router. Type 0x84 area, advertised by the Area Border Router. Type 0x84
summary-LSA describes the reachability of Area Border Routers summary-LSA describes the reachability of Area Border Routers
and AS border routers and their TE capabilities. and AS border routers and their TE capabilities.
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ABR from the same area the ASBR is located in. ABR from the same area the ASBR is located in.
Summary-router-TE flags Summary-router-TE flags
Bit E - When set, the advertised Link-State ID is an AS boundary Bit E - When set, the advertised Link-State ID is an AS boundary
router (E is for external). The advertising router and router (E is for external). The advertising router and
the Link State ID belong to the same area. the Link State ID belong to the same area.
Bit B - When set, the advertised Link state ID is an Area Bit B - When set, the advertised Link state ID is an Area
border router (B is for Border) border router (B is for Border)
Router-TE flags, Router-TE flags,
Router-TE TLVs (TE capabilities of the link-state-ID router) Router-TE TLVs (TE capabilities of the link-state-ID router)
TE Flags and TE TLVs are as applicable to the ABR/ASBR TE Flags and TE TLVs are as applicable to the ABR/ASBR
specified in the link state ID. The semantics is same as specified in the link state ID. The semantics is same as
specified in the Router-TE LSA. specified in the Router-TE LSA.
9.5. TE-AS-external LSAs (0x85) 9.5. TE-AS-external LSAs (0x85)
TE-AS-external-LSAs are the Type 0x85 LSAs. This is modeled after TE-AS-external-LSAs are the Type 0x85 LSAs. This is modeled after
AS-external LSA format and flooding scope. These LSAs are originated AS-external LSA format and flooding scope. These LSAs are originated
by AS boundary routers with TE extensions (say, a BGP node which can by AS boundary routers with TE extensions (say, a BGP node which can
communicate MPLS labels across to external ASes), and describe communicate MPLS labels across to external ASes), and describe
networks and pre-engineered TE links external to the AS. The networks and pre-established TE links external to the AS. The
flooding scope of this LSA is similar to that of an AS-external LSA. flooding scope of this LSA is similar to that of an AS-external LSA.
I.e., AS wide, with the exception of stub areas. I.e., AS wide, with the exception of stub areas.
0 1 2 3 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 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 | 0x85 | | LS age | Options | 0x85 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link State ID | | Link State ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Network Mask Network Mask
The IP address mask for the advertised TE destination. For The IP address mask for the advertised TE destination. For
example, this can be used to specify access to a specific example, this can be used to specify access to a specific
TE-node or TE-link with an mask of 0xffffffff. This can also TE-node or TE-link with an mask of 0xffffffff. This can also
be used to specify access to an aggregated set of destinations be used to specify access to an aggregated set of destinations
using a different mask, ex: 0xff000000. using a different mask, ex: 0xff000000.
Link-TE flags, Link-TE flags,
Link-TE TLVs Link-TE TLVs
The TE attributes of this route. These fields are optional and The TE attributes of this route. These fields are optional and
are provided only when one or more pre-engineered circuits can are provided only when one or more pre-established circuits can
be specified with the advertisement. Without these fields, be specified with the advertisement. Without these fields,
the LSA will simply state TE reachability info. the LSA will simply state TE reachability info.
Forwarding address Forwarding address
Data traffic for the advertised destination will be forwarded to Data traffic for the advertised destination will be forwarded to
this address. If the Forwarding address is set to 0.0.0.0, data this address. If the Forwarding address is set to 0.0.0.0, data
traffic will be forwarded instead to the LSA's originator (i.e., traffic will be forwarded instead to the LSA's originator (i.e.,
the responsible AS boundary router). the responsible AS boundary router).
External Route Tag External Route Tag
skipping to change at page 36, line 29 skipping to change at page 37, line 38
Below, we assume a TE network that is composed of three OSPF areas, Below, we assume a TE network that is composed of three OSPF areas,
namely Area-1, Area-2 and Area-3, attached together through the namely Area-1, Area-2 and Area-3, attached together through the
backbone area. The following figure is an inter-area topology backbone area. The following figure is an inter-area topology
abstraction from the perspective of routers in Area-1. The abstraction from the perspective of routers in Area-1. The
abstraction is similar, but not the same, as that of the non-TE abstraction is similar, but not the same, as that of the non-TE
abstraction. As such, the authors claim the model is easy to abstraction. As such, the authors claim the model is easy to
understand and emulate. The abstraction illustrates reachability understand and emulate. The abstraction illustrates reachability
of TE networks and nodes in areas external to the local area and of TE networks and nodes in areas external to the local area and
ASes external to the local AS. The abstraction also illustrates ASes external to the local AS. The abstraction also illustrates
pre-engineered TE links that may be advertised by ABRs and ASBRs. pre-established TE links that may be advertised by ABRs and ASBRs.
Area-1 an has a single border router, ABR-A1 and no ASBRs. Area-2 Area-1 an has a single border router, ABR-A1 and no ASBRs. Area-2
has an Area border router ABR-A2 and an AS border router ASBR-S1. has an Area border router ABR-A2 and an AS border router ASBR-S1.
Area-3 has two Area border routers ABR-A2 and ABR-A3; and an AS Area-3 has two Area border routers ABR-A2 and ABR-A3; and an AS
border router ASBR-S2. There may be any number of Pre-engineered border router ASBR-S2. There may be any number of Pre-engineered
TE links amongst ABRs and ASBRs. The following example assumes a TE links amongst ABRs and ASBRs. The following example assumes a
single TE-link between ABR-A1 and ABR-A2; between ABR-A1 and single TE-link between ABR-A1 and ABR-A2; between ABR-A1 and
ABR-A3; between ABR-A2 to ASBR-S1; and between ABR-A3 to ASBR-S2. ABR-A3; between ABR-A2 to ASBR-S1; and between ABR-A3 to ASBR-S2.
All Area border routers and AS border routers are assumed to All Area border routers and AS border routers are assumed to
be represented by their TE capabilities. be represented by their TE capabilities.
skipping to change at page 41, line 35 skipping to change at page 42, line 35
[OPQLSA-GMPLS] Kompella, K., Y. Rekhter, A. Banerjee, J. Drake, [OPQLSA-GMPLS] Kompella, K., Y. Rekhter, A. Banerjee, J. Drake,
G. Bernstein, D. Fedyk, E. Mannie, D. Saha and G. Bernstein, D. Fedyk, E. Mannie, D. Saha and
V. Sharma, "OSPF Extensions in Support of Generalized V. Sharma, "OSPF Extensions in Support of Generalized
MPLS", <draft-ietf-ccamp-ospf-gmpls-extensions-01.txt>, MPLS", <draft-ietf-ccamp-ospf-gmpls-extensions-01.txt>,
work in progress. work in progress.
Authors' Addresses Authors' Addresses
Pyda Srisuresh Pyda Srisuresh
Kuokoa Networks, Inc. Kuokoa Networks, Inc.
2901 Tasman Dr., Suite 202 475 Potrero Avenue
Santa Clara, CA 95054 Sunnyvale, CA 94085
U.S.A. U.S.A.
EMail: srisuresh@yahoo.com EMail: srisuresh@yahoo.com
Paul Joseph Paul Joseph
Vivace Networks Force10 Networks
2730 Orchard Parkway 1440 McCarthy Boulevard
San Jose, CA 95134 Milpitas, CA 95035
U.S.A. U.S.A.
Tel: (408) 432 7655 EMail: pjoseph@Force10Networks.com
EMail: paul.joseph@vivacenetworks.com
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