Internet DRAFT - draft-dhody-pce-bn-discovery-ospf
draft-dhody-pce-bn-discovery-ospf
PCE Working Group D. Dhody
Internet-Draft U. Palle
Intended status: Experimental Huawei Technologies India Pvt Ltd
Expires: March 19, 2015 September 15, 2014
OSPF Protocol Extensions for Boundary Node Discovery (BND)
draft-dhody-pce-bn-discovery-ospf-09
Abstract
The Path Computation Element (PCE) may be used for computing multi-
domain (Area or AS) Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) Traffic Engineered (TE) Label Switch Path
(LSP).
In this circumstance, it is highly desirable to be able to
dynamically and automatically discover a set of Boundary Nodes (BN)
along with their domain information in a simple way. For that
purpose, this document defines extensions to the Open Shortest Path
First (OSPF) routing protocol for the advertisement of Boundary Node
(BN) Discovery information within an OSPF area or within the entire
OSPF routing domain.
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
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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."
This Internet-Draft will expire on March 19, 2015.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
Dhody & Palle Expires March 19, 2015 [Page 1]
Internet-Draft OSPF BND September 2014
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Applications . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Existing Mechanisms . . . . . . . . . . . . . . . . . . . . . 6
4.1. OSPF LSA . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2. Inter-AS TE Link . . . . . . . . . . . . . . . . . . . . 6
4.3. OSPF Area Topology . . . . . . . . . . . . . . . . . . . 8
5. Other Considerations . . . . . . . . . . . . . . . . . . . . 8
5.1. Static Configurations . . . . . . . . . . . . . . . . . . 8
5.2. Importance of Domain Information along with BNs . . . . . 8
5.3. Relationship to Domain-Sequence . . . . . . . . . . . . . 9
6. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. Boundary Node (BN) Discovery Information . . . . . . . . 9
6.2. Flooding Scope . . . . . . . . . . . . . . . . . . . . . 9
7. The OSPF BND TLV . . . . . . . . . . . . . . . . . . . . . . 9
7.1. BN-ADDRESS Sub-TLV . . . . . . . . . . . . . . . . . . . 10
7.2. BN-DOMAIN Sub-TLV . . . . . . . . . . . . . . . . . . . . 11
8. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 12
9. Backward Compatibility . . . . . . . . . . . . . . . . . . . 13
10. Impact on Network . . . . . . . . . . . . . . . . . . . . . . 13
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
11.1. OSPF TLV . . . . . . . . . . . . . . . . . . . . . . . . 13
12. Security Considerations . . . . . . . . . . . . . . . . . . . 14
13. Manageability Considerations . . . . . . . . . . . . . . . . 14
14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
15.1. Normative References . . . . . . . . . . . . . . . . . . 14
15.2. Informative References . . . . . . . . . . . . . . . . . 15
1. Introduction
This document defines extensions to OSPFv2 [RFC2328] and OSPFv3
[RFC5340] to allow a boundary node in an OSPF routing domain to
advertise its location, along with domain information.
Generic capability advertisement mechanisms for OSPF are defined in
[RFC4970]. These allow a router to advertise its capabilities within
Dhody & Palle Expires March 19, 2015 [Page 2]
Internet-Draft OSPF BND September 2014
an OSPF area or an entire OSPF routing domain. This document
leverages this generic capability advertisement mechanism to fully
satisfy the dynamic BN discovery.
This document defines a new TLV (named the Boundary Node Discovery
TLV (BND TLV)) to be carried within the OSPF Router Information LSA
([RFC4970]).
The Boundary Node information advertised is detailed in Section 6.
Protocol extensions and procedures are defined in Section 7 and
Section 8.
A detailed description about the need for auto discovery of Boundary
Nodes (BN) and thier domains is also provided in this document.
The OSPF extensions defined in this document allow for Boundary Node
discovery within an OSPF routing domain. Boundary Node can be an
Area Border Router (ABR) or Autonomous System Border Router (ASBR).
1.1. 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 [RFC2119].
2. Terminology
The following terminology is used in this document.
ABR: OSPF Area Border Router. Routers used to connect two IGP
areas.
AS: Autonomous System.
ASBR: Autonomous System Border Router. Router used to connect
together ASes of the same or different service providers via one
or more inter-AS links
BN: A boundary node is either an ABR in the context of inter-area
Traffic Engineering or an ASBR in the context of inter-AS Traffic
Engineering.
BND: Boundary Node Discovery
BRPC: Backward Recursive Path Computation
Domain: Any collection of network elements within a common sphere of
address management or path computational responsibility. Examples
Dhody & Palle Expires March 19, 2015 [Page 3]
Internet-Draft OSPF BND September 2014
of domains include Interior Gateway Protocol (IGP) areas and
Autonomous Systems (ASs).
H-PCE: Hierarchical PCE.
IGP: Interior Gateway Protocol. Either of the two routing
protocols, Open Shortest Path First (OSPF) or Intermediate System
to Intermediate System (IS-IS).
LSA: Link State Advertisement.
OSPF: Open Shortest Path First.
PCE: Path Computation Element. An entity (component, application,
or network node) that is capable of computing a network path or
route based on a network graph and applying computational
constraints.
TLV: Type-Length-Variable data encoding.
3. Applications
Backward Recursive Path Computation (BRPC) procedure as defined in
[RFC5441], requires Path Computation Element (PCE) [RFC4655] to be
aware of the Boundary Nodes (BN) for the inter-domain path
computation. This information would be either statically configured
at PCE or learned via some mechanism, as listed in Section 4.
In case of static configuration, as shown in the Figure 1, incase of
OSPF Area0, configuration of BNs at PCE5 is extensive. BRPC
procedure guarantees a best path only if BNs are selected correctly,
any change in BNs at run time may lead to sub-optimal path. Also
Administrator need to configure ABR / ASBR ID in such a way that it
is reachable from all the domains, BND TLV can take care of this
automatically.
Dhody & Palle Expires March 19, 2015 [Page 4]
Internet-Draft OSPF BND September 2014
+--------------------+
| +-----+|
| Area 2 | PCE2||
| +-----+|
| |
| |
| BN4+----+ |
+--------+----+------+
+----------+----+---------+
| +----+ |
| |
| |
| |
+---------------+ | |+----------------+
| BN1 | | || BN5 |
| +-+-++ +++--+ |
| | | || ||| | |
| +-+-++ +++--+ |
| | | || |
| BN2 | | || BN6 |
| +-+-++ Area 0 +++--+ |
| Area 1 | | || ||| | Area 3 |
| +-+-++ +++--+ |
| | | || |
| BN3 | | +-----+ || BN7 |
|+-----+ +-+-++ | PCE5| +++--+ +-----+ |
|| PCE1| | | || +-----+ ||| | | PCE3| |
|+-----+ +-+-++ +++--+ +-----+ |
| | | || |
+---------------+ | |+----------------+
| |
| |
| +----+ |
+----------+----+---------+
+--------+----+------+
| BN8 +----+ |
| |
| |
| Area 4 +-----+|
| | PCE4||
| +-----+|
+--------------------+
Figure 1: OSPF Area Topology
The problems with existing mechanism to discover Boundary nodes are
listed in Section 4.
Dhody & Palle Expires March 19, 2015 [Page 5]
Internet-Draft OSPF BND September 2014
Hierarchal PCE (H-PCE) [RFC6805] mechanim MAY require a parent PCE to
be aware of child domain's boundary node, child PCE in any case
should be aware of all its boundary nodes and can use mechnims as
described in this document.
4. Existing Mechanisms
4.1. OSPF LSA
o E bit and B bit of Router LSA defined in [RFC2328] can help in
finding a router acting as ABR/ASBR but there is no way to find
out the domain information of this ABR/ASBR. As stated in
Section 5.2, Selection of correct BN is based on domain and thus
it is ineffective.
o Selection of ABR based on summary LSA or ASBR based on AS-external
LSA is not a good idea, first it requires PCE to look into the
OSPF core data structure - Link State Database (LSDB) thus adding
to coupling, second it MAY require Border Gateway Protocol (BGP)
routes to be redistributed into OSPF which is also not a good
network design principle.
4.2. Inter-AS TE Link
o [RFC5392] specifies how to advertise TE properties of inter-AS
links; through which ASBR and remote AS can be discovered, but ABR
and their domain information cannot be discovered via above RFC.
o AS is made up of multiple Area, there maybe a need to clearly
identify a BN by combination of both AS number and Area-id. Refer
[DOMAIN-SEQ].
o AS shown in below figure, just the knowledge of AS 100 and AS 200
is not sufficient, the BN should have both AS and Area
information. The area information cannot be provided by
[RFC5392].
Dhody & Palle Expires March 19, 2015 [Page 6]
Internet-Draft OSPF BND September 2014
|
| +-------------+ +----------------+
| |Area 2 | |Area 4 |
| | +--+| | +--+ |
| | | || | | | |
| | +--+ +--+| | +--+ +--+ |
| | | | | | | | |
| | *--+ | | +--+ |
| | / +--+ | | +--+ |
| |/ | | | | | | |
| / +--+ | | +--+ +--+ |
| /| +--+ |+--------------+| | | |
|/ | | | ++-+ +-++ +--+ |
+-------------+/ | +--+ || | | || |
| /| | ++-+ +-++ |
| +--*|| +-------------+| |+----------------+
| | ||| | +--+ |
| +--+|| | | | |
| +--+ || | +--+ |
| | | || | |
| +--+ || | |
| || | +--+ |
|+--+ || | | | |
|| | || | +--+ |
|+--+ || | |
| || | +--+ |
| +--+ || +------------+ | | | |+----------------+
| | | || |Area 3 +-++ +--+ +-++ Area 5 |
| +--+ || | | || | || |
| || | +-++ +-++ |
| +--+|| | +--+ | | Area 0 || +--+ |
| | ||| | | | | +--------------+| | | |
| +--*|| | +--+ | | +--+ |
| \| | | | +--+ |
|Area 1 |\ | +--+ | | +--+ | | |
+-------------+|\ | | | | | | | +--+ |
| \| +--+ +--+ | +--+ |
| \ | | | |
| |\ +--+ | +--+ |
| | \ +--+ | | | | |
| | \| | | | +--+ |
| | *--+ | | |
| | | | |
| +------------+ +----------------+
|
|
As 100 | AS 200
|
Dhody & Palle Expires March 19, 2015 [Page 7]
Internet-Draft OSPF BND September 2014
4.3. OSPF Area Topology
o Consider OSPF topology as shown in Figure 1, One can make a
generalization that all ABR connects to Area 0, and one doesnt
need the area information.
o But as per [RFC3509], there are alternative interpretaion of ABR,
which needs to be considered. If there is a connectivity between
Area 1 and Area 2 directly that needs to be considered. In the
scope of path computation. it is not correct to force all paths to
go through area 0, irrespective of actual topology.
. .
. Area 0 .
+--+ +--+
..|R1|.. ..|R2|..
. +--+ .. +--+ .
. .. .
. +--+ .
. Area1 |R3| Area2 .
. +--+ +--+ .
. .. |R4| .
. . . +--+ .
....... .......
5. Other Considerations
5.1. Static Configurations
A simple solution would be to configure BNs (ABR and ASBR) at PCE(s)
along with their domain information. As this information is fairly
static this could work in simple situations. But as PCE are being
used in bigger and multiple domains, any sort of static
configurations would put extra effort on the system administrator.
Selection of correct BNs is the core of any inter-domain path
computation procedure, this information should be dynamically learned
and maintained.
5.2. Importance of Domain Information along with BNs
There are methods to learn BNs dynamically from IGP, but the
knowledge of neighboring-domains is not possible to obtain. Without
this the correct BN based on the domain-path can not be selected.
[RFC5441] mentions:
"Note that PCE(i) only considers the entry BNs of domain(i), i.e.,
only the BNs that provide connectivity from domain(i-1). In other
Dhody & Palle Expires March 19, 2015 [Page 8]
Internet-Draft OSPF BND September 2014
words, the set BN-en(k,i) is only made of those BNs that provide
connectivity from domain (i-1) to domain(i)."
This selection of correct BNs providing connectivity between correct
domains cannot be made by the information obtained from IGP. Without
the correct selection we would not be following [RFC5441].
5.3. Relationship to Domain-Sequence
[DOMAIN-SEQ] provides a standard representation of Domain Sequence in
all deployment scenarios. The Domain Information carried in the BN-
DOMAIN sub-tlv is same as the sub-objects inside the domain sequence.
6. Overview
6.1. Boundary Node (BN) Discovery Information
The BN discovery information is composed of:
o The BN location: an IPv4 and/or IPv6 address that is used to reach
the BN. It is RECOMMENDED to use an address that is always
reachable from all connected domains;
o The set of two or more Domain(s) into which the BN has
connectivity;
Changes in BN discovery information may occur as a result of BN
configuration update or domain status change.
6.2. Flooding Scope
The flooding scope for BN information advertised through OSPF can be
limited to OSPF area(s) the BN belongs to, or can be extended across
the entire OSPF routing domain.
7. The OSPF BND TLV
The OSPF BN Discovery TLV (BND TLV) contains a non-ordered set of
sub-TLVs.
The format of the OSPF BND TLV and its sub-TLVs is identical to the
TLV format used by the Traffic Engineering Extensions to OSPF
[RFC3630]. That is, the TLV is composed of 2 octets for the type, 2
octets specifying the TLV length, and a value field. The Length
field defines the length of the value portion in octets.
The OSPF BND TLV has the following format:
Dhody & Palle Expires March 19, 2015 [Page 9]
Internet-Draft OSPF BND September 2014
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// sub-TLVs //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: To be assigned by IANA (suggested value 8)
Length: Variable
Value: This comprises of following sub-TLVs
Two sub-TLVs are defined:
Sub-TLV type Length Name
1 variable BN-ADDRESS sub-TLV
2 4 BN-DOMAIN sub-TLV
The BN-ADDRESS and BN-DOMAIN sub-TLVs MUST always be present within
the BND TLV.
Malformed BND TLVs or sub-TLVs not explicitly described in this
document MUST cause the LSA to be treated as malformed according to
the normal procedures of OSPF.
Any unrecognized sub-TLV MUST be silently ignored.
The BND TLV is carried within an OSPF Router Information LSA defined
in [RFC4970].
The following sub-sections describe the sub-TLVs which are carried
within the BND TLV.
7.1. BN-ADDRESS Sub-TLV
The BN-ADDRESS sub-TLV specifies an IP address that can be used to
reach the BN. It is RECOMMENDED to make use of an address that is
always reachable, provided that the BN is alive and reachable.
The BN-ADDRESS sub-TLV is mandatory; it MUST be present within the
BND TLV. It MAY appear twice, when the BN has both an IPv4 and IPv6
address. It MUST NOT appear more than once for the same address
type. If it appears more than once for the same address type, only
the first occurrence is processed and any others MUST be ignored.
The format of the BN-ADDRESS sub-TLV is as follows:
Dhody & Palle Expires March 19, 2015 [Page 10]
Internet-Draft OSPF BND September 2014
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 = 1 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| address-type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// BN IP Address //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
BN-ADDRESS sub-TLV format
Type: 1
Length: 8 (IPv4) or 20 (IPv6)
Address-type:
1 IPv4
2 IPv6
Reserved: SHOULD be set to zero on transmission and MUST be ignored
on receipt.
BN IP Address: The IP address to be used to reach the BN.
7.2. BN-DOMAIN Sub-TLV
The BN-DOMAIN sub-TLV specifies a BN-Domain (area or AS) where the BN
has topology connectivity.
The BN-DOMAIN sub-TLV is mandatory; it MUST be present within the BND
TLV.
A BND TLV MUST include two or more BN-DOMAIN sub-TLVs as the BN has
connectivity into multiple BN-Domains.
The BN-DOMAIN sub-TLV has the following format:
Dhody & Palle Expires March 19, 2015 [Page 11]
Internet-Draft OSPF BND September 2014
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 = 2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Domain-type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Domain ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
BN-DOMAIN sub-TLV format
Type: 2
Length: 8
Two domain-type values are defined:
1 OSPF Area ID
2 AS Number
Domain ID: With the domain-type set to 1, this indicates the 32-bit
Area ID of an area where the BN (ABR) has connectivity. With domain-
type set to 2, this indicates an AS number of an AS where the BN
(ASBR) has connectivity. When the AS number is coded in two octets,
the AS Number field MUST have its first two octets set to 0.
8. Elements of Procedure
The BND TLV is advertised within OSPFv2 Router Information LSAs
(Opaque type of 4 and Opaque ID of 0) or OSPFv3 Router Information
LSAs (function code of 12), which are defined in [RFC4970]. As such,
elements of procedure are inherited from those defined in [RFC4970].
In OSPFv2, the flooding scope is controlled by the opaque LSA type(as
defined in [RFC5250]) and in OSPFv3, by the S1/S2 bits (as defined in
[RFC5340]). If the flooding scope is area local, then the BND TLV
MUST be carried within an OSPFv2 type 10 router information LSA or an
OSPFV3 Router Information LSA with the S1 bit set and the S2 bit
clear. If the flooding scope is the entire IGP domain, then the BND
TLV MUST be carried within an OSPFv2 type 11 Router Information LSA
or OSPFv3 Router Information LSA with the S1 bit clear and the S2 bit
set.
When the BN function is deactivated, the OSPF speaker MUST originate
a new Router Information LSA that no longer includes the
corresponding BND TLV, provided there are other TLVs in the LSA. If
there are no other TLVs in the LSA, it MUST either send an empty
Router Information LSA or purge it by prematurely aging it.
Dhody & Palle Expires March 19, 2015 [Page 12]
Internet-Draft OSPF BND September 2014
The BN address (i.e., the address indicated within the BN-ADDRESS
sub-TLV) SHOULD be reachable via some prefixes advertised by OSPF.
The BND TLV information regarding a specific BN is only considered
current and useable when the router advertising this information is
itself reachable via OSPF calculated paths in the same area of the
LSA in which the BND TLV appears.
A change in the state of a BN (activate, deactivate, domain change)
MUST result in a corresponding change in the BND TLV information
advertised by an OSPF router (inserted, removed, updated)in its LSA.
The way BNs determine the information they advertise, and how that
information is made available to OSPF, is out of the scope of this
document. Some information may be configured and other information
may be automatically determined by the OSPF.
A change in information in the BND TLV MUST NOT trigger any SPF
computation at a receiving router.
9. Backward Compatibility
The BND TLV defined in this document does not introduce any
interoperability issues.
A router not supporting the BND TLV will just silently ignore the TLV
as specified in [RFC4970].
10. Impact on Network
The routers acting as BNs will originate Opaque LSA with BND Tlv; As
there are only few BNs exist in the network, the performance impact
in flooding is very less.
11. IANA Considerations
11.1. OSPF TLV
IANA has defined a registry for TLVs carried in the Router
Information LSA defined in [RFC4970]. A number of IANA
considerations have been highlighted in previous sections of this
document. IANA is requested to make the following allocations.
Value TLV Name Reference
----- -------- ----------
To be BND (this document)
assigned
by IANA
Dhody & Palle Expires March 19, 2015 [Page 13]
Internet-Draft OSPF BND September 2014
12. Security Considerations
This document defines OSPF extensions for BN discovery within an
administrative domain. Hence the security of the BN discovery relies
on the security of OSPF.
Mechanisms defined to ensure authenticity and integrity of OSPF LSAs
[RFC2154], and their TLVs, can be used to secure the BN Discovery
information as well.
OSPF provides no encryption mechanism for protecting the privacy of
LSAs and, in particular, the privacy of the BN discovery information.
13. Manageability Considerations
TBD
14. Acknowledgments
We would like to thank Quintin Zhao, Daniel King, Adrian Ferral,
Suresh babu, Pradeep Shastry, Saravana Kumar, Srinivasan and
Venugopal Reddy for their useful comments and suggestions.
15. References
15.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with
Digital Signatures", RFC 2154, June 1997.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[RFC4970] Lindem, A., Shen, N., Vasseur, JP., Aggarwal, R., and S.
Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 4970, July 2007.
[RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The
OSPF Opaque LSA Option", RFC 5250, July 2008.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, July 2008.
Dhody & Palle Expires March 19, 2015 [Page 14]
Internet-Draft OSPF BND September 2014
15.2. Informative References
[RFC3509] Zinin, A., Lindem, A., and D. Yeung, "Alternative
Implementations of OSPF Area Border Routers", RFC 3509,
April 2003.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630, September
2003.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC5392] Chen, M., Zhang, R., and X. Duan, "OSPF Extensions in
Support of Inter-Autonomous System (AS) MPLS and GMPLS
Traffic Engineering", RFC 5392, January 2009.
[RFC5441] Vasseur, JP., Zhang, R., Bitar, N., and JL. Le Roux, "A
Backward-Recursive PCE-Based Computation (BRPC) Procedure
to Compute Shortest Constrained Inter-Domain Traffic
Engineering Label Switched Paths", RFC 5441, April 2009.
[RFC6805] King, D. and A. Farrel, "The Application of the Path
Computation Element Architecture to the Determination of a
Sequence of Domains in MPLS and GMPLS", RFC 6805, November
2012.
[DOMAIN-SEQ]
Dhody, D., Palle, U., and R. Casellas, "Standard
Representation Of Domain Sequence (draft-ietf-pce-pcep-
domain-sequence-05)", July 2014.
Authors' Addresses
Dhruv Dhody
Huawei Technologies India Pvt Ltd
Leela Palace
Bangalore, Karnataka 560008
India
EMail: dhruv.ietf@gmail.com
Dhody & Palle Expires March 19, 2015 [Page 15]
Internet-Draft OSPF BND September 2014
Udayasree Palle
Huawei Technologies India Pvt Ltd
Leela Palace
Bangalore, Karnataka 560008
India
EMail: udayasree.palle@huawei.com
Dhody & Palle Expires March 19, 2015 [Page 16]
