draft-ietf-ccamp-gmpls-ason-routing-ospf-03.txt   draft-ietf-ccamp-gmpls-ason-routing-ospf-04.txt 
Network Working Group Dimitri Papadimitriou Network Working Group Dimitri Papadimitriou
Internet Draft (Alcatel) Internet Draft (Alcatel-Lucent)
Category: Standard Category: Standards Track
OSPFv2 Routing Protocols Extensions for ASON Routing Created: December 7, 2007
Expires: June 7, 2008
draft-ietf-ccamp-gmpls-ason-routing-ospf-03.txt OSPFv2 Extensions for ASON Routing
draft-ietf-ccamp-gmpls-ason-routing-ospf-04.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
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
skipping to change at line 47 skipping to change at page 2, line 5
The Generalized MPLS (GMPLS) suite of protocols has been defined to The Generalized MPLS (GMPLS) suite of protocols has been defined to
control different switching technologies as well as different control different switching technologies as well as different
applications. These include support for requesting TDM connections applications. These include support for requesting TDM connections
including SONET/SDH and Optical Transport Networks (OTNs). including SONET/SDH and Optical Transport Networks (OTNs).
This document provides the extensions of the OSPFv2 Link State This document provides the extensions of the OSPFv2 Link State
Routing Protocol to meet the routing requirements for an Routing Protocol to meet the routing requirements for an
Automatically Switched Optical Network (ASON) as defined by ITU-T. Automatically Switched Optical Network (ASON) as defined by ITU-T.
D.Papadimitriou et al. - Expires September 2007 1 Table of Contents
1. Conventions used in this document 1. Conventions Used In This Document .............................. 2
2. Introduction
3. Reachability
3.1 Node IPv4 Local Prefix Sub-TLV
3.2 Node IPv6 Local Prefix Sub-TLV
4. Link Attribute
4.1 Local Adaptation
4.2 Bandwidth Accounting
5. Routing Information Scope
5.1. Terminology and Identification
5.2 Link Advertisement (Local and Remote TE Router ID Sub-TLV)
5.3 Reachability Advertisement (Local TE Router ID Sub-TLV)
6. Routing Information Dissemination
6.1 Import/Export Rules
6.2 Discovery and Selection
6.2.1 Upward Discovery and Selection
6.2.2 Downward Discovery and Selection
6.3 Loop Prevention
6.3.1 Associated Area ID
6.3.2 Processing
6.4 Resiliency
6.5 Neighbor Relationship and Routing Adjacency
6.6 Reconfiguration
7. OSPFv2 Extensions
7.1 Compatibility
7.2 Scalability
8. Security Considerations
9. IANA Considerations
10. Acknowledgements
11. References
11.1 Normative References
11.2 Informative References
12. Author's Address
Appendix 1: ASON Terminology
Appendix 2: ASON Routing Terminology
1. Conventions Used In This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
The reader is assumed to be familiar with the terminology and The reader is assumed to be familiar with the terminology and
requirements developed in [RFC4258] and the evaluation outcomes requirements developed in [RFC4258] and the evaluation outcomes
detailed in [ASON-EVAL]. detailed in [RFC4652].
2. Introduction 2. Introduction
There are certain capabilities that are needed to support the ITU-T There are certain capabilities that are needed to support the ITU-T
Automatically Switched Optical Network (ASON) control plane Automatically Switched Optical Network (ASON) control plane
architecture as defined in [G.8080]. architecture as defined in [G.8080].
[RFC4258] details the routing requirements for the GMPLS suite of [RFC4258] details the routing requirements for the GMPLS suite of
routing protocols to support the capabilities and functionality of routing protocols to support the capabilities and functionality of
ASON control planes identified in [G.7715] and in [G.7715.1]. ASON control planes identified in [G.7715] and in [G.7715.1].
[RFC4652] evaluates the IETF Link State Routing Protocols against the [RFC4652] evaluates the IETF Link State Routing Protocols against the
requirements identified in [RFC4258]. Section 7.1 of [RFC4652] requirements identified in [RFC4258]. Section 7.1 of [RFC4652]
summarizes the capabilities to be provided by OSPFv2 [RFC2328] in summarizes the capabilities to be provided by OSPFv2 [RFC2328] in
support of ASON routing. From the candidate routing protocols support of ASON routing. From the candidate routing protocols
identified in [RFC4652] (OSPFv2 and IS-IS), this document details the identified in [RFC4652] (OSPFv2 and IS-IS), this document details the
OSPFv2 specifics for ASON routing. OSPFv2 specifics for ASON routing.
Note that here is no implied relationship between multi-layer Note that here is no implied relationship between multi-layer
transport networks and multi-level routing [RFC4652]. transport networks and multi-level routing [RFC4652]. This mechanism
works either for single layer or multi-layer networks.
Implementations MAY support a hierarchical routing topology (multi- Implementations MAY support a hierarchical routing topology (multi-
level) for multiple transport switching layers and/or a hierarchical level) for multiple transport network layers and/or a hierarchical
routing topology for one transport switching layer. routing topology for a single transport network layer.
This document details the processing of the generic (technology This document details the processing of the generic (technology
independent) link attributes that are defined in this document and independent) link attributes that are defined in this document and
in [RFC3630], [RFC4202], and [RFC4203]. As detailed in Section 4.2, in [RFC3630], [RFC4202], and [RFC4203]. As detailed in Section 4.2,
technology specific traffic engineering attributes (and their technology specific traffic engineering attributes (and their
processing) MAY complement this document. processing) MAY complement this document.
ASON (Routing) terminology sections are provided in Appendix 1 and 2. ASON (Routing) terminology sections are provided in Appendix 1 and 2.
3. Reachability 3. Reachability
In order to advertise blocks of reachable address prefixes a In order to advertise blocks of reachable address prefixes a
summarization mechanism is introduced that complements the summarization mechanism is introduced that complements the
techniques described in [OSPF-NODE]. techniques described in [OSPF-NODE].
This extension takes the form of a network mask (a 32-bit number This extension takes the form of a network mask (a 32-bit number
indicating the range of IP addresses residing on a single IP indicating the range of IP addresses residing on a single IP
network/subnet). The set of local addresses are carried in an OSPFv2 network/subnet). The set of local addresses are carried in an OSPFv2
TE LSA node attribute TLV (a specific sub-TLV is defined per address TE LSA node attribute TLV (a specific sub-TLV is defined per address
family, e.g., IPv4 and IPv6). family, e.g., IPv4 and IPv6 used as network-unique identifiers).
D.Papadimitriou et al. - Expires September 2007 2
The proposed solution is to advertise the local address prefixes of The proposed solution is to advertise the local address prefixes of
a router as new sub-TLVs of the (OSPFv2 TE LSA) Node Attribute top a router as new sub-TLVs of the (OSPFv2 TE LSA) Node Attribute top
level TLV (of Type TBD). This document defines the following sub- level TLV (of Type TBD). This document defines the following sub-
TLVs: TLVs:
- Node IPv4 Local Prefix sub-TLV: Type 3 - Length: variable - Node IPv4 Local Prefix sub-TLV: Type 3 - Length: variable
- Node IPv6 Local Prefix sub-TLV: Type 4 - Length: variable - Node IPv6 Local Prefix sub-TLV: Type 4 - Length: variable
3.1 Node IPv4 local prefix sub-TLV 3.1 Node IPv4 Local Prefix Sub-TLV
The node IPv4 local prefix sub-TLV has a type of 3 and contains one The node IPv4 local prefix sub-TLV has a type of 3 and contains one
or more local IPv4 prefixes. It has the following format: or more local IPv4 prefixes. It has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 3 | Length | | 3 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Mask 1 | | Network Mask 1 |
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for the advertised destination prefix. for the advertised destination prefix.
Each <Network mask, IPv4 Address> pair listed as part of this sub- Each <Network mask, IPv4 Address> pair listed as part of this sub-
TLV represents a reachable destination prefix hosted by the TLV represents a reachable destination prefix hosted by the
advertising Router ID. advertising Router ID.
The local addresses that can be learned from TE LSAs i.e. router The local addresses that can be learned from TE LSAs i.e. router
address and TE interface addresses SHOULD not be advertised in the address and TE interface addresses SHOULD not be advertised in the
node IPv4 local prefix sub-TLV. node IPv4 local prefix sub-TLV.
3.2 Node IPv6 local prefix sub-TLV 3.2 Node IPv6 Local Prefix Sub-TLV
The node IPv6 local prefix sub-TLV has a type of 4 and contains one The node IPv6 local prefix sub-TLV has a type of 4 and contains one
or more local IPv6 prefixes. IPv6 Prefix Representation uses RFC or more local IPv6 prefixes. IPv6 Prefix Representation uses RFC
2740 Section A.4.1. It has the following format: 2740 Section A.4.1. It has the following format:
D.Papadimitriou et al. - Expires September 2007 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4 | Length | | 4 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PrefixLength | PrefixOptions | (0) | | PrefixLength | PrefixOptions | (0) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| IPv6 Address Prefix 1 | | IPv6 Address Prefix 1 |
| | | |
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The Local Adaptation is defined as TE link attribute (i.e. sub-TLV) The Local Adaptation is defined as TE link attribute (i.e. sub-TLV)
that describes the cross/inter-layer relationships. that describes the cross/inter-layer relationships.
The Interface Switching Capability Descriptor (ISCD) TE Attribute The Interface Switching Capability Descriptor (ISCD) TE Attribute
[RFC4202] identifies the ability of the TE link to support cross- [RFC4202] identifies the ability of the TE link to support cross-
connection to another link within the same layer and the ability to connection to another link within the same layer and the ability to
use a locally terminated connection that belongs to one layer as a use a locally terminated connection that belongs to one layer as a
data link for another layer (adaptation capability). However, the data link for another layer (adaptation capability). However, the
information associated to the ability to terminate connections information associated to the ability to terminate connections
D.Papadimitriou et al. - Expires September 2007 4
within that layer (referred to as the termination capability) is within that layer (referred to as the termination capability) is
embedded with the adaptation capability. embedded with the adaptation capability.
For instance, a link between two optical cross-connects will contain For instance, a link between two optical cross-connects will contain
at least one ISCD attribute describing LSC switching capability. at least one ISCD attribute describing LSC switching capability.
Whereas a link between an optical cross-connect and an IP/MPLS LSR Whereas a link between an optical cross-connect and an IP/MPLS LSR
will contain at least two ISCD attributes: one for the description will contain at least two ISCD attributes: one for the description
of the LSC termination capability and one for the PSC adaptation of the LSC termination capability and one for the PSC adaptation
capability. capability.
In OSPFv2, the Interface Switching Capability Descriptor is a sub- In OSPFv2, the Interface Switching Capability Descriptor is a sub-
TLV (of type 15) of the top-level Link TLV (of type 2) [RFC4203]. TLV (of type 15) of the top-level Link TLV (of type 2) [RFC4203].
The adaptation and termination capabilities are advertised using two The adaptation and termination capabilities are advertised using two
separate ISCD sub-TLVs within the same top-level link TLV. separate ISCD sub-TLVs within the same top-level link TLV.
Per [RFC4202] and [RFC4203], an interface MAY have more than one Per [RFC4202] and [RFC4203], an interface MAY have more than one
ISCD sub-TLV. Hence, the corresponding advertisements should not ISCD sub-TLV. Hence, the corresponding advertisements should not
result in any compatibility issue. result in any compatibility issue.
Further refinement of the ISCD sub-TLV for multi-layer networks is
outside the scope of this document.
4.2 Bandwidth Accounting 4.2 Bandwidth Accounting
GMPLS Routing defines an Interface Switching Capability Descriptor GMPLS Routing defines an Interface Switching Capability Descriptor
(ISCD) that delivers among others the information about the (ISCD) that delivers among others the information about the
(maximum/minimum) bandwidth per priority an LSP can make use of. (maximum/minimum) bandwidth per priority an LSP can make use of.
Per [RFC4202] and [RFC4203], one or more ISCD sub-TLVs can be Per [RFC4202] and [RFC4203], one or more ISCD sub-TLVs can be
associated to an interface. This information combined with the associated to an interface. This information combined with the
Unreserved Bandwidth (sub-TLV defined in [RFC3630], Section 2.5.8) Unreserved Bandwidth (sub-TLV defined in [RFC3630], Section 2.5.8)
provides for the base bandwidth accounting. provides for the base bandwidth accounting.
In the ASON context, additional optional and informational In the ASON context, additional information may be included when the
accounting information may be included in the technology specific
field of the ISCD sub-TLV according to the technology supported. For
example, when the switching capability field is set to indicate TDM,
additional optional and informational accounting information may be
included per timeslot. This information may be included when the
representation and information in the other advertised fields are representation and information in the other advertised fields are
not sufficient for the specific technology. not sufficient for a specific technology (e.g., SDH). The definition
of technology-specific information elements is beyond the scope of
The definition of processing rules for technology-specific this document. Some technologies will not require additional
information elements are beyond the scope of this document. Some information beyond what is already contained in the advertisements.
technologies will not require additional information beyond what is
already contained in the advertisements, but others may require the
addition of further data carried in the technology specific field of
the ISCD sub-TLB. When included, the format and encoding of such
data MUST follow the rules defined in [RFC4202], and the presence
and processing rules MUST be defined in a separate document.
5. Routing Information Scope 5. Routing Information Scope
5.1. Terminology and Identification 5.1. Terminology and Identification
D.Papadimitriou et al. - Expires September 2007 5
o) Pi is a physical (bearer/data/transport plane) node. o) Pi is a physical (bearer/data/transport plane) node.
o) Li is a logical control plane entity that is associated to a o) Li is a logical control plane entity that is associated to a
single data plane (abstract) node. Each Li is identified by a unique single data plane (abstract) node. Each Li is identified by a
TE Router_ID. The latter is a control plane identifier, defined as unique TE Router_ID. The latter is a control plane identifier,
the Router_Address top level TLV of the Type 1 TE LSA [RFC3630]. defined as the Router_Address top level TLV of the Type 1 TE LSA
[RFC3630].
Note: the Router_Address top-level TLV definition, processing and Note: the Router_Address top-level TLV definition, processing and
usage remain per [RFC3630]. This TLV specifies a stable IP address usage remain per [RFC3630]. This TLV specifies a stable IP address
of the advertising router (Ri) that is always reachable if there is of the advertising router (Ri) that is always reachable if there
any IP connectivity to it. Moreover, each advertising router is any IP connectivity to it (e.g. via the Data Communication
advertises a unique, reachable IP address for each Pi on behalf of Network). Moreover, each advertising router advertises a unique,
which it makes advertisements. reachable IP address for each Pi on behalf of which it makes
advertisements.
o) Ri is a logical control plane entity that is associated to a o) Ri is a logical control plane entity that is associated to a
control plane "router". The latter is the source for topology control plane "router". The latter is the source for topology
information that it generates and shares with other control plane information that it generates and shares with other control plane
"routers". The Ri is identified by the (advertising) Router_ID (32- "routers". The Ri is identified by the (advertising) Router_ID
bit) [RFC2328]. (32-bit) [RFC2328].
The Router_ID, which is represented by Ri and which corresponds to The Router_ID, which is represented by Ri and which corresponds to
the RC_ID [RFC4258], does not enter into the identification of the the RC_ID [RFC4258], does not enter into the identification of the
logical entities representing the data plane resources such as logical entities representing the data plane resources such as
links. The Routing DataBase (RDB) is associated to the Ri. links. The Routing DataBase (RDB) is associated to the Ri.
Aside from the Li/Pi mappings, these identifiers are not assumed to Aside from the Li/Pi mappings, these identifiers are not assumed to
be in a particular entity relationship except that the Ri may have be in a particular entity relationship except that the Ri may have
multiple Lis in its scope. The relationship between Ri and Li is multiple Lis in its scope. The relationship between Ri and Li is
simple at any moment in time: an Li may be advertised by only one Ri simple at any moment in time: an Li may be advertised by only one Ri
at any time. However, an Ri may advertise a set of one or more Lis. at any time. However, an Ri may advertise a set of one or more Lis.
Hence, the OSPFv2 routing protocol must support a single Ri Hence, the OSPFv2 routing protocol must support a single Ri
advertising on behalf of more than one Li. advertising on behalf of more than one Li.
5.2 Link Advertisement (Local and Remote TE Router ID sub-TLV) 5.2 Link Advertisement (Local and Remote TE Router ID Sub-TLV)
A Router_ID (Ri) advertising on behalf multiple TE Router_IDs (Lis) A Router_ID (Ri) advertising on behalf multiple TE Router_IDs (Lis)
creates a 1:N relationship between the Router_ID and the TE creates a 1:N relationship between the Router_ID and the TE
Router_ID. As the link local and link remote (unnumbered) ID Router_ID. As the link local and link remote (unnumbered) ID
association is not unique per node (per Li unicity), the association is not unique per node (per Li unicity), the
advertisement needs to indicate the remote Lj value and rely on the advertisement needs to indicate the remote Lj value and rely on the
initial discovery process to retrieve the [Li;Lj] relationship. In initial discovery process to retrieve the [Li;Lj] relationship. In
brief, as unnumbered links have their ID defined on per Li bases, brief, as unnumbered links have their ID defined on per Li bases,
the remote Lj needs to be identified to scope the link remote ID to the remote Lj needs to be identified to scope the link remote ID to
the local Li. Therefore, the routing protocol MUST be able to the local Li. Therefore, the routing protocol MUST be able to
disambiguate the advertised TE links so that they can be associated disambiguate the advertised TE links so that they can be associated
with the correct TE Router ID. with the correct TE Router ID.
For this purpose, a new sub-TLV of the (OSPFv2 TE LSA) top level For this purpose, a new sub-TLV of the (OSPFv2 TE LSA) top level
Link TLV is introduced that defines the local and the remote Link TLV is introduced that defines the local and the remote
TE_Router_ID. TE_Router_ID.
D.Papadimitriou et al. - Expires September 2007 6
The type of this sub-TLV is 17, and length is eight octets. The The type of this sub-TLV is 17, and length is eight octets. The
value field of this sub-TLV contains four octets of Local TE Router value field of this sub-TLV contains four octets of Local TE Router
Identifier followed by four octets of Remote TE Router Identifier. Identifier followed by four octets of Remote TE Router Identifier.
The value of the Local and the Remote TE Router Identifier SHOULD The value of the Local and the Remote TE Router Identifier SHOULD
NOT be set to 0. NOT be set to 0.
The format of this sub-TLV is the following: The format of this sub-TLV is the following:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 17 | Length | | 17 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local TE Router Identifier | | Local TE Router Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote TE Router Identifier | | Remote TE Router Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This sub-TLV is optional and SHOULD only be included as part of the This sub-TLV is only required be included as part of the top level
top level Link TLV if the Router_ID is advertising on behalf of more Link TLV if the Router_ID is advertising on behalf of more than one
than one TE_Router_ID. In any other case, this sub-TLV SHOULD be TE_Router_ID. In any other case, this sub-TLV SHOULD be omitted
omitted except if operator plans to start of with 1 Li and except if operator plans to start of with 1 Li and progressively add
progressively add more Li's (under the same Ri) such as to maintain more Li's (under the same Ri) such as to maintain consistency.
consistency.
Note: The Link ID sub-TLV that identifies the other end of the link Note: The Link ID sub-TLV that identifies the other end of the link
(i.e. Router ID of the neighbor for point-to-point links) MUST (i.e. Router ID of the neighbor for point-to-point links) MUST
appear exactly once per Link TLV. This sub-TLV MUST be processed as appear exactly once per Link TLV. This sub-TLV MUST be processed as
defined in [RFC3630]. defined in [RFC3630].
5.3 Reachability Advertisement (Local TE Router ID sub-TLV) 5.3 Reachability Advertisement (Local TE Router ID Sub-TLV)
When the Router_ID advertises on behalf of multiple TE Router_IDs When the Router_ID advertises on behalf of multiple TE Router_IDs
(Lis), the routing protocol MUST be able to associate the advertised (Lis), the routing protocol MUST be able to associate the advertised
reachability information with the correct TE Router ID. reachability information with the correct TE Router ID.
For this purpose, a new sub-TLV of the (OSPFv2 TE LSA) top level For this purpose, a new sub-TLV of the (OSPFv2 TE LSA) top level
Node Attribute TLV is introduced. This TLV associates the local Node Attribute TLV is introduced. This TLV associates the local
prefixes (sub-TLV 3 and 4, see above) to a given TE Router_ID. prefixes (sub-TLV 3 and 4, see above) to a given TE Router_ID.
The type of this sub-TLV is 5, and length is four octets. The value The type of this sub-TLV is 5, and length is four octets. The value
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Identifier [RFC3630]. Identifier [RFC3630].
The format of this sub-TLV is the following: The format of this sub-TLV is the following:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 5 | Length | | 5 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local TE Router Identifier | | Local TE Router Identifier |
D.Papadimitriou et al. - Expires September 2007 7
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This sub-TLV is optional and SHOULD only be included as part of the This sub-TLV is only required to be included be included as part of
Node Attribute TLV if the Router_ID is advertising on behalf of more the Node Attribute TLV if the Router_ID is advertising on behalf of
than one TE_Router_ID. In any other case, this sub-TLV SHOULD be more than one TE_Router_ID. In any other case, this sub-TLV SHOULD
omitted. be omitted.
6. Routing Information Dissemination 6. Routing Information Dissemination
An ASON RA represents a partition of the data plane and its An ASON RA represents a partition of the data plane and its
identifier is used within the control plane as the representation of identifier is used within the control plane as the representation of
this partition. A RA may contain smaller RAs inter-connected by this partition. A RA may contain smaller RAs inter-connected by
links. The limit of the subdivision results in a RA that contains two links. The limit of the subdivision results in a RA that contains two
sub-networks interconnected by a single link. ASON RA levels do not sub-networks interconnected by a single link. ASON RA levels do not
reflect routing protocol levels (such as OSPF areas). OSPF routing reflect routing protocol levels (such as OSPF areas). OSPF routing
areas containing routing areas that recursively define successive areas containing routing areas that recursively define successive
skipping to change at line 406 skipping to change at page 10, line 6
6.1 Import/Export Rules 6.1 Import/Export Rules
RCs supporting RAs disseminate downward/upward the hierarchy by RCs supporting RAs disseminate downward/upward the hierarchy by
importing/exporting this routing information as Opaque TE LSA importing/exporting this routing information as Opaque TE LSA
(Opaque Type 1) of LS Type 10. The information that MAY be exchanged (Opaque Type 1) of LS Type 10. The information that MAY be exchanged
between adjacent levels includes the Router_Address, Link and between adjacent levels includes the Router_Address, Link and
Node_Attribute top level TLV. Node_Attribute top level TLV.
The Opaque TE LSA import/export rules are governed as follows: The Opaque TE LSA import/export rules are governed as follows:
- If the export target interface is associated to the same area as - If the export target interface is associated to the same area as
the one associated with the import interface, the Opaque LSA MUST the one associated with the import interface, the Opaque LSA MUST
NOT imported. NOT imported.
- If a match is found between the Advertising Router ID in the - If a match is found between the Advertising Router ID in the
header of the received Opaque TE LSA and one of the Router ID header of the received Opaque TE LSA and one of the Router ID
belonging to the area of the export target interface, the Opaque belonging to the area of the export target interface, the Opaque
LSA MUST NOT be imported. LSA MUST NOT be imported.
- If these two conditions are not met the Opaque TE LSA MAY be - If these two conditions are not met the Opaque TE LSA MAY be
imported and MAY be disseminated following the OSPF flooding imported and MAY be disseminated following the OSPF flooding
rules. The Advertising Router ID is set to the importing routers rules. The Advertising Router ID is set to the importing router's
router ID. router ID.
D.Papadimitriou et al. - Expires September 2007 8
The imported/exported routing information content MAY be transformed The imported/exported routing information content MAY be transformed
e.g. filtered or aggregated, as long as the resulting routing e.g. filtered or aggregated, as long as the resulting routing
information is consistent. In particular, when more than one RC are information is consistent. In particular, when more than one RC are
bound to adjacent levels and both are allowed to import/export bound to adjacent levels and both are allowed to import/export
routing information it is expected that these transformation are routing information it is expected that these transformation are
performed in consistent manner. Definition of these policy-based performed in consistent manner. Definition of these policy-based
mechanisms is outside the scope of this document. mechanisms is outside the scope of this document.
In practice, and in order to avoid scalability and processing In practice, and in order to avoid scalability and processing
overhead, routing information imported/exported downward/upward the overhead, routing information imported/exported downward/upward the
hierarchy is expected to include reachability information (see hierarchy is expected to include reachability information (see
Section 3) and upon strict policy control link topology information. Section 3) and upon strict policy control link topology information.
6.2 Discovery and Selection 6.2 Discovery and Selection
6.2.1 Upward Discovery and Selection 6.2.1 Upward Discovery and Selection
In order to discover RCs that are capable to disseminate routing In order to discover RCs that are capable to disseminate routing
information upward the routing hierarchy, the following Capability information upward the routing hierarchy, the following Capability
Descriptor bit [OSPF-CAP] are defined: Descriptor bit [RFC4970] are defined:
- U bit: when set, this flag indicates that the RC is capable to - U bit: when set, this flag indicates that the RC is capable to
disseminate routing information upward the adjacent level. disseminate routing information upward the adjacent level.
In case of multiple RC are advertized with their U bit set, the RC In case of multiple RC are advertized with their U bit set, the RC
with the highest Router ID, among the RCs having set the U bit, with the highest Router ID, among the RCs having set the U bit,
SHOULD be selected as the RC for upward dissemination of routing SHOULD be selected as the RC for upward dissemination of routing
information. The other RCs MUST NOT participate in the upward information. The other RCs MUST NOT participate in the upward
dissemination of routing information as long as the opaque LSA dissemination of routing information as long as the opaque LSA
information corresponding to the highest Router ID RC does not reach information corresponding to the highest Router ID RC does not reach
skipping to change at line 472 skipping to change at page 11, line 25
6.2.2 Downward Discovery and Selection 6.2.2 Downward Discovery and Selection
The same discovery mechanism is used for selecting the RC taking in The same discovery mechanism is used for selecting the RC taking in
charge dissemination of routing information downward the hierarchy. charge dissemination of routing information downward the hierarchy.
However, an additional restriction MUST be applied such that the RC However, an additional restriction MUST be applied such that the RC
selection process takes into account that an upper level may be selection process takes into account that an upper level may be
adjacent to one or more lower (routing area) levels. For this adjacent to one or more lower (routing area) levels. For this
purpose a specific TLV indexing the (lower) area ID to which the purpose a specific TLV indexing the (lower) area ID to which the
RC's are capable to disseminate routing information is needed. RC's are capable to disseminate routing information is needed.
D.Papadimitriou et al. - Expires September 2007 9
OSPF Downstream Associated Area ID TLV format carried in the OSPF OSPF Downstream Associated Area ID TLV format carried in the OSPF
router information LSA [OSPF-CAP] is defined. This TLV has the router information LSA [RFC4970] is defined. This TLV has the
following format: following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Associated Area ID | | Associated Area ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
skipping to change at line 492 skipping to change at page 11, line 44
| Associated Area ID | | Associated Area ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// ... // // ... //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Associated Area ID | | Associated Area ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type (16 bits): identifies the TLV type Type (16 bits): identifies the TLV type
Length (16 bits): length of the value field in octets Length (16 bits): length of the value field in octets
Value (n x 32 bits): Associated Area ID whose value space is the Value (n x 32 bits): Associated Area ID whose value space is the
Area ID as defined in [RFC2328]. Area ID as defined in [RFC2328].
Note that this information MUST be present when the D bit is set. To Note that this information MUST be present when the D bit is set. To
discover RCs that are capable to disseminate routing information discover RCs that are capable to disseminate routing information
downward the routing hierarchy, the following Capability Descriptor downward the routing hierarchy, the following Capability Descriptor
bit [OSPF-CAP] is defined, that MUST be advertised together with the bit [RFC4970] is defined, that MUST be advertised together with the
OSPF Downstream Associated Area ID TLV: OSPF Downstream Associated Area ID TLV:
- D bit: when set, this flag indicates that the RC is capable to - D bit: when set, this flag indicates that the RC is capable to
disseminate routing information downward the adjacent level(s). disseminate routing information downward the adjacent level(s).
In case of multiple supporting RCs for the same Associated Area ID, In case of multiple supporting RCs for the same Associated Area ID,
the RC with the highest Router ID, among the RCs having set the D the RC with the highest Router ID, among the RCs having set the D
bit, MUST be selected as the RC for downward dissemination of bit, MUST be selected as the RC for downward dissemination of
routing information. The other RCs for the same Associated Area ID routing information. The other RCs for the same Associated Area ID
MUST not participate in the downward dissemination of routing MUST NOT participate in the downward dissemination of routing
information as long as the opaque LSA information corresponding to information as long as the opaque LSA information corresponding to
the highest Router ID RC does not reach MaxAge. This mechanism the highest Router ID RC does not reach MaxAge. This mechanism
prevents from having more than one RC advertizing routing prevents from having more than one RC advertizing routing
information downward the routing hierarchy. information downward the routing hierarchy.
Note that alternatively if this information cannot be discovered Note that alternatively if this information cannot be discovered
automatically, it MUST be manually configured. automatically, it MUST be manually configured.
The OSPF Router information opaque LSA (opaque type of 4, opaque ID The OSPF Router information opaque LSA (opaque type of 4, opaque ID
of 0) and its content in particular, the Router Informational of 0) and its content in particular, the Router Informational
Capabilities TLV [OSPF-CAP] and TE Node Capability Descriptor TLV Capabilities TLV [RFC4970] and TE Node Capability Descriptor TLV
[OSPF-TE-CAP] MUST NOT be re-originated. [OSPF-TE-CAP] MUST NOT be re-originated.
6.3 Loop prevention 6.3 Loop Prevention
D.Papadimitriou et al. - Expires September 2007 10
When more than one RC are bound to adjacent levels of the hierarchy, When more than one RC are bound to adjacent levels of the hierarchy,
configured and selected to redistribute upward and downward the configured and selected to redistribute upward and downward the
routing information, a specific mechanism is required to avoid routing information, a specific mechanism is required to avoid
looping/re-introduction of routing information back to the upper looping/re-introduction of routing information back to the upper
level. This specific case occurs e.g. when the RC advertizing level. This specific case occurs e.g. when the RC advertizing
routing information downward the hierarchy is not the one routing information downward the hierarchy is not the one
advertizing routing upward the hierarchy (or vice-versa). advertizing routing upward the hierarchy (or vice-versa).
When these conditions are met, it is necessary to have a mean by When these conditions are met, it is necessary to have a mean by
which an RC receiving an Opaque TE LSA imported/exported downward by which an RC receiving an Opaque TE LSA imported/exported downward by
skipping to change at line 576 skipping to change at page 13, line 37
6.3.1 Associated Area ID 6.3.1 Associated Area ID
Thus, we need some way of filtering the downward/upward re- Thus, we need some way of filtering the downward/upward re-
originated Opaque TE LSA. Per [RFC2370], the information contained originated Opaque TE LSA. Per [RFC2370], the information contained
in Opaque LSAs may be used directly by OSPF. Henceforth, by adding in Opaque LSAs may be used directly by OSPF. Henceforth, by adding
the Area ID associated to the incoming routing information the loop the Area ID associated to the incoming routing information the loop
prevention problem can be solved. This additional information that prevention problem can be solved. This additional information that
MAY be carried in opaque LSAs including the Router Address TLV, in MAY be carried in opaque LSAs including the Router Address TLV, in
opaque LSAs including the Link TLV, and in opaque LSAs including the opaque LSAs including the Link TLV, and in opaque LSAs including the
Node Attribute TLV, is referred to as the Associated Area ID. Node Attribute TLV, is referred to as the Associated Area ID. The
Associated Area ID reflects the identifier of the area from which
the routing information is received. For example, for a multiple
level hierarchy, this identifier does not reflect the originating
Area ID, it will reflect the area from which the routing information
is imported.
D.Papadimitriou et al. - Expires September 2007 11
The format of the Associated Area ID TLV is defined as follows: The format of the Associated Area ID TLV is defined as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Associated Area ID | | Associated Area ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type (16 bits): identifies the TLV type Type (16 bits): identifies the TLV type
Length (16 bits): length of the value field in octets Length (16 bits): length of the value field in octets
Value (32 bits): Associated Area ID whose value space is the Area ID Value (32 bits): Associated Area ID whose value space is the Area ID
as defined in [RFC2328]. as defined in [RFC2328].
6.3.2 Processing 6.3.2 Processing
When fulfilling the rules detailed in Section 6.1 a given Opaque LSA When fulfilling the rules detailed in Section 6.1 a given Opaque LSA
is imported/exported downward or upward the routing hierarchy, the is imported/exported downward or upward the routing hierarchy, the
Associated Area ID TLV is added to the received opaque LSA list of Associated Area ID TLV is added to the received opaque LSA list of
TLVs such as to identify the area from where this routing TLVs such as to identify the area from which this routing
information has been received. information has been received.
When the RC adjacent to the lower or upper level routing level When the RC adjacent to the lower or upper level routing level
receives this opaque LSA, the following rule is applied (in addition receives this opaque LSA, the following rule is applied (in addition
the rule governing the import/export of opaque LSAs as detailed in the rule governing the import/export of opaque LSAs as detailed in
Section 6.1). Section 6.1).
- If a match is found between the Associated Area ID of the received - If a match is found between the Associated Area ID of the received
Opaque TE LSA and the Area ID belonging to the area of the export Opaque TE LSA and the Area ID belonging to the area of the export
target interface, the Opaque LSA MUST NOT be imported. target interface, the Opaque TE LSA MUST NOT be imported.
- Otherwise, this opaque LSA MAY be imported and disseminated - Otherwise, this opaque LSA MAY be imported and disseminated
downward or upward the routing hierarchy following the OSPF downward or upward the routing hierarchy following the OSPF
flooding rules. flooding rules.
This mechanism ensures that no race condition occurs when the This mechanism ensures that no race condition occurs when the
conditions depicted in Figure 2 are met. conditions depicted in Figure 2 are met.
RC_5 ------------- RC_6 RC_5 ------------- RC_6
| | | |
| | Area Y | | Area Y
********* ********* ********* *********
..........* RC_1a *.........* RC_2a *............ ..........* RC_1a *.........* RC_2a *............
__________* | * * | * __________* | * * | *
..........* RC_1b *.........* RC 2b *............ ..........* RC_1b *.........* RC 2b *............
********* ********* ********* *********
| | | |
| | Area X | | Area X
RC_3 --- . . . --- RC_4 RC_3 --- . . . --- RC_4
D.Papadimitriou et al. - Expires September 2007 12
Figure 2. Race Condition Prevention (Example) Figure 2. Race Condition Prevention (Example)
Assume that RC_1b is configured for exporting routing information Assume that RC_1b is configured for exporting routing information
upward toward Area Y (upward the routing hierarchy) and that RC_2a upward toward Area Y (upward the routing hierarchy) and that RC_2a
is configured for exporting routing information toward Area X is configured for exporting routing information toward Area X
(downward the routing hierarchy). (downward the routing hierarchy).
Assumes that routing information advertised by RC_3 would reach Assumes that routing information advertised by RC_3 would reach
faster to RC_4 across Area Y through hierarchy. faster to RC_4 across Area Y through hierarchy.
If RC_2b is not able to prevent from importing that information, If RC_2b is not able to prevent from importing that information,
RC_4 may receive that information before the same advertisement RC_4 may receive that information before the same advertisement
would propagate in Area X (from RC 3) to RC_4. would propagate in Area X (from RC 3) to RC_4. For this purpose RC
1a inserts the Associated Area X to the imported routing information
from Area X. Because RC 2b finds a match between the Associated Area
ID (X) of the received Opaque TE LSA and the ID (X) of area of the
export target interface, this LSA MUST NOT be imported.
6.4 Resiliency 6.4 Resiliency
OSPF creates adjacencies between neighboring routers for the purpose OSPF creates adjacencies between neighboring routers for the purpose
of exchanging routing information. After a neighbor has been of exchanging routing information. After a neighbor has been
discovered, bidirectional communication is ensured, and a routing discovered, bidirectional communication is ensured, and a routing
adjacency is formed between RCs, loss of communication may result in adjacency is formed between RCs, loss of communication may result in
partitioned areas. partitioned areas.
Consider for instance (see Figure 2.) the case where RC_1a and RC 1b Consider for instance (see Figure 2.) the case where RC_1a and RC 1b
skipping to change at line 681 skipping to change at page 16, line 5
provisioned/configured between RCs belonging to the same routing provisioned/configured between RCs belonging to the same routing
level. Provisioning/configuration techniques are outside the scope level. Provisioning/configuration techniques are outside the scope
of this document. of this document.
Once established, the OSPF Hello Protocol is responsible for Once established, the OSPF Hello Protocol is responsible for
establishing and maintaining neighbor relationships. This protocol establishing and maintaining neighbor relationships. This protocol
also ensures that communication between neighbors is bidirectional. also ensures that communication between neighbors is bidirectional.
Routing adjacency can subsequently be formed between RCs following Routing adjacency can subsequently be formed between RCs following
mechanisms defined in [RFC2328]. mechanisms defined in [RFC2328].
7. OSPFv2 Extensions 6.6 Reconfiguration
D.Papadimitriou et al. - Expires September 2007 13 This section details the Area ID reconfiguration steps.
Reconfiguration of the Area ID occurs when the Area ID is modified
e.g. from value Z to value X or Y (see Fig.2).
The process of reconfiguring the Area ID involves:
- Disable the import/export of routing information from the upper
and lower level (to prevent any LS information update)
- Change the Area ID of the local level Area e.g. from Z to X or Y.
Perform an LSDB checksum on all routers to verify that LSDB are
consistent.
- Enable import of upstream and downstream routing information such
as to re-synchronize local level LSDB from any LS information that
may have occurred in an upper or a lower routing level.
- Enable export of routing information downstream such as to re-sync
the downstream level with the newly reconfigured Area ID (as part
of the re-advertised Opaque TE LSA).
- Enable export of routing information upstream such as to re-sync
the upstream level with the newly reconfigured Area ID (as part of
the re-advertised Opaque TE LSA).
Note that the re-sync operation needs only to be ensured with the
directly adjacent upper and lower routing level.
7. OSPFv2 Extensions
7.1 Compatibility 7.1 Compatibility
Extensions specified in this document are associated to the Extensions specified in this document are associated to the
Opaque TE LSA: Opaque TE LSA:
o) Router Address top level TLV (Type 1): o) Router Address top level TLV (Type 1):
- Associated Area ID sub-TLV: optional sub-TLV for loop avoidance - Associated Area ID sub-TLV: optional sub-TLV for loop avoidance
(see Section 6.2) (see Section 6.2)
skipping to change at line 714 skipping to change at page 17, line 17
- Node IPv6 Local Prefix sub-TLV: optional sub-TLV for IPv6 - Node IPv6 Local Prefix sub-TLV: optional sub-TLV for IPv6
reachability advertisement reachability advertisement
- Local TE Router ID sub-TLV: optional sub-TLV for scoping - Local TE Router ID sub-TLV: optional sub-TLV for scoping
reachability per TE_Router ID reachability per TE_Router ID
- Associated Area ID sub-TLV: optional sub-TLV for loop avoidance - Associated Area ID sub-TLV: optional sub-TLV for loop avoidance
(see Section 6.3) (see Section 6.3)
Opaque RI LSA: Opaque RI LSA:
o) Routing information dissemination o) Routing information dissemination
- U bit in Capability Descriptor TLV [OSPF-CAP] - U bit in Capability Descriptor TLV [RFC4970]
- D bit in Capability Descriptor TLV [OSPF-CAP] - D bit in Capability Descriptor TLV [RFC4970]
- Downstream Associated Area ID TLV in the OSPF Routing - Downstream Associated Area ID TLV in the OSPF Routing
Information LSA [OSPF-CAP] Information LSA [RFC4970]
7.2 Scalability 7.2 Scalability
o) Routing information exchange upward/downward the hierarchy o) Routing information exchange upward/downward the hierarchy
between adjacent areas SHOULD by default be limited to reachability. between adjacent areas SHOULD by default be limited to reachability.
In addition, several transformations such as prefix aggregation are In addition, several transformations such as prefix aggregation are
recommended when allowing decreasing the amount of information recommended when allowing decreasing the amount of information
imported/exported by a given RC without impacting consistency. imported/exported by a given RC without impacting consistency.
o) Routing information exchange upward/downward the hierarchy when o) Routing information exchange upward/downward the hierarchy when
involving TE attributes MUST be under strict policy control. Pacing involving TE attributes MUST be under strict policy control. Pacing
and min/max thresholds for triggered updates are strongly and min/max thresholds for triggered updates are strongly
recommended. recommended.
o) The number of routing levels MUST be maintained under strict o) The number of routing levels MUST be maintained under strict
policy control. policy control.
8. Acknowledgements 8. Security Considerations
This section to be updated in a future revision.
9. IANA Considerations
This section to be updated in a future revision.
10. Acknowledgements
D.Papadimitriou et al. - Expires September 2007 14
The authors would like to thank Dean Cheng, Acee Lindem, Pandian The authors would like to thank Dean Cheng, Acee Lindem, Pandian
Vijay, Alan Davey and Adrian Farrel for their useful comments and Vijay, Alan Davey, Adrian Farrel, and Deborah Brungard for their
suggestions. useful comments and suggestions.
9. References Question 14 of Study Group 15 of the ITU-T provided useful and
constructive input.
9.1 Normative References 11. References
[OSPF-NODE] R.Aggarwal, and K.Kompella, "Advertising a Router's 11.1 Normative References
Local Addresses in OSPF TE Extensions," Internet Draft,
(work in progress), draft-ietf-ospf-te-node-addr-
02.txt, March 2005.
[OSPF-CAP] A.Lindem et al. "Extensions to OSPF for Advertising [OSPF-NODE] R.Aggarwal, and K.Kompella, "Advertising a Router's
Optional Router Capabilities", Work in progress, draft- Local Addresses in OSPF TE Extensions",
ietf-ospf-cap-08.txt, November 2005. draft-ietf-ospf-te-node-addr, work in progress.
[RFC2026] S.Bradner, "The Internet Standards Process -- [RFC2026] S.Bradner, "The Internet Standards Process --
Revision 3", BCP 9, RFC 2026, October 1996. Revision 3", BCP 9, RFC 2026, October 1996.
[RFC2328] J.Moy, "OSPF Version 2", RFC 2328, April 1998. [RFC2328] J.Moy, "OSPF Version 2", RFC 2328, April 1998.
[RFC2370] R.Coltun, "The OSPF Opaque LSA Option", RFC 2370, July [RFC2370] R.Coltun, "The OSPF Opaque LSA Option", RFC 2370, July
1998. 1998.
[RFC2740] R.Coltun et al. "OSPF for IPv6", RFC 2740, December [RFC2740] R.Coltun et al. "OSPF for IPv6", RFC 2740, December
skipping to change at line 776 skipping to change at page 18, line 34
[RFC2119] S.Bradner, "Key words for use in RFCs to Indicate [RFC2119] S.Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3477] K.Kompella et al. "Signalling Unnumbered Links in [RFC3477] K.Kompella et al. "Signalling Unnumbered Links in
Resource ReSerVation Protocol - Traffic Engineering Resource ReSerVation Protocol - Traffic Engineering
(RSVP-TE)", RFC 3477, January 2003. (RSVP-TE)", RFC 3477, January 2003.
[RFC3630] D.Katz et al. "Traffic Engineering (TE) Extensions to [RFC3630] D.Katz et al. "Traffic Engineering (TE) Extensions to
OSPF Version 2", RFC 3630, September 2003. OSPF Version 2", RFC 3630, September 2003.
[RFC3667] S.Bradner, "IETF Rights in Contributions", BCP 78,
RFC 3667, February 2004.
[RFC3668] S.Bradner, Ed., "Intellectual Property Rights in IETF
Technology", BCP 79, RFC 3668, February 2004.
[RFC3946] E.Mannie, and D.Papadimitriou, (Editors) et al.,
"Generalized Multi-Protocol Label Switching Extensions
for SONET and SDH Control," RFC 3946, October 2004.
[RFC4202] Kompella, K. (Editor) et al., "Routing Extensions in [RFC4202] Kompella, K. (Editor) et al., "Routing Extensions in
Support of Generalized MPLS," RFC 4202, October 2005. Support of Generalized MPLS", RFC 4202, October 2005.
D.Papadimitriou et al. - Expires September 2007 15
[RFC4203] Kompella, K. (Editor) et al., "OSPF Extensions in [RFC4203] Kompella, K. (Editor) et al., "OSPF Extensions in
Support of Generalized Multi-Protocol Label Switching Support of Generalized Multi-Protocol Label Switching
(GMPLS)," RFC 4203, October 2005. (GMPLS)", RFC 4203, October 2005.
8.2 Informative References [RFC4606] E.Mannie, and D.Papadimitriou, (Editors) et al.,
"Generalized Multi-Protocol Label Switching Extensions
for SONET and SDH Control", RFC 4606, August 2006.
[RFC4970] A.Lindem et al. "Extensions to OSPF for Advertising
Optional Router Capabilities", RFC 4970, July 2007.
11.2 Informative References
[OSPF-TE-CAP]J.P. Vasseur et al., "Routing extensions for discovery [OSPF-TE-CAP]J.P. Vasseur et al., "Routing extensions for discovery
of Traffic Engineering Node Capabilities", Work in of Traffic Engineering Node Capabilities",
draft-ietf-ccamp-te-node-cap, work in progress.
[RFC4258] D.Brungard et al. "Requirements for Generalized MPLS [RFC4258] D.Brungard et al. "Requirements for Generalized MPLS
(GMPLS) Routing for Automatically Switched Optical (GMPLS) Routing for Automatically Switched Optical
Network (ASON)," RFC 4258, November 2005. Network (ASON)", RFC 4258, November 2005.
[RFC4652] D.Papadimitriou (Ed.) et al. "Evaluation of existing [RFC4652] D.Papadimitriou (Ed.) et al. "Evaluation of existing
Routing Protocols against ASON Routing Requirements", Routing Protocols against ASON Routing Requirements",
RFC 4652, October 2006. RFC 4652, October 2006.
For information on the availability of ITU Documents, please see For information on the availability of ITU Documents, please see
http://www.itu.int http://www.itu.int
[G.7715] ITU-T Rec. G.7715/Y.1306, "Architecture and [G.7715] ITU-T Rec. G.7715/Y.1306, "Architecture and
Requirements for the Automatically Switched Optical Requirements for the Automatically Switched Optical
Network (ASON)," June 2002. Network (ASON)", June 2002.
[G.7715.1] ITU-T Draft Rec. G.7715.1/Y.1706.1, "ASON Routing [G.7715.1] ITU-T Draft Rec. G.7715.1/Y.1706.1, "ASON Routing
Architecture and Requirements for Link State Protocols," Architecture and Requirements for Link State
November 2003. Protocols", November 2003.
[G.8080] ITU-T Rec. G.8080/Y.1304, "Architecture for the [G.8080] ITU-T Rec. G.8080/Y.1304, "Architecture for the
Automatically Switched Optical Network (ASON)," Automatically Switched Optical Network (ASON)",
November 2001 (and Revision, January 2003). November 2001 (and Revision, January 2003).
9. Author's Addresses 12. Author's Address
Dimitri Papadimitriou (Alcatel) Dimitri Papadimitriou (Alcatel)
Francis Wellensplein 1, Francis Wellensplein 1,
B-2018 Antwerpen, Belgium B-2018 Antwerpen, Belgium
Phone: +32 3 2408491 Phone: +32 3 2408491
EMail: dimitri.papadimitriou@alcatel.be EMail: dimitri.papadimitriou@alcatel-lucent.be
D.Papadimitriou et al. - Expires September 2007 16
Appendix 1: ASON Terminology Appendix 1: ASON Terminology
This document makes use of the following terms: This document makes use of the following terms:
Administrative domain: (see Recommendation G.805) for the purposes of Administrative domain: (see Recommendation G.805) for the purposes of
[G7715.1] an administrative domain represents the extent of resources [G7715.1] an administrative domain represents the extent of resources
which belong to a single player such as a network operator, a service which belong to a single player such as a network operator, a service
provider, or an end-user. Administrative domains of different players provider, or an end-user. Administrative domains of different players
do not overlap amongst themselves. do not overlap amongst themselves.
skipping to change at line 883 skipping to change at page 21, line 7
as configuration, security, (FCAPS), for the purpose of providing as configuration, security, (FCAPS), for the purpose of providing
control in a consistent manner. Management domains can be disjoint, control in a consistent manner. Management domains can be disjoint,
contained or overlapping. As such the resources within an contained or overlapping. As such the resources within an
administrative domain can be distributed into several possible administrative domain can be distributed into several possible
overlapping management domains. The same resource can therefore overlapping management domains. The same resource can therefore
belong to several management domains simultaneously, but a management belong to several management domains simultaneously, but a management
domain shall not cross the border of an administrative domain. domain shall not cross the border of an administrative domain.
Subnetwork Point (SNP): The SNP is a control plane abstraction that Subnetwork Point (SNP): The SNP is a control plane abstraction that
represents an actual or potential transport plane resource. SNPs (in represents an actual or potential transport plane resource. SNPs (in
D.Papadimitriou et al. - Expires September 2007 17
different subnetwork partitions) may represent the same transport different subnetwork partitions) may represent the same transport
resource. A one-to-one correspondence should not be assumed. resource. A one-to-one correspondence should not be assumed.
Subnetwork Point Pool (SNPP): A set of SNPs that are grouped together Subnetwork Point Pool (SNPP): A set of SNPs that are grouped together
for the purposes of routing. for the purposes of routing.
Termination Connection Point (TCP): A TCP represents the output of a Termination Connection Point (TCP): A TCP represents the output of a
Trail Termination function or the input to a Trail Termination Sink Trail Termination function or the input to a Trail Termination Sink
function. function.
Transport plane: provides bi-directional or unidirectional transfer Transport plane: provides bi-directional or unidirectional transfer
of user information, from one location to another. It can also of user information, from one location to another. It can also
provide transfer of some control and network management information. provide transfer of some control and network management information.
The Transport Plane is layered; it is equivalent to the Transport The Transport Plane is layered; it is equivalent to the Transport
Network defined in G.805 Recommendation. Network defined in G.805 Recommendation.
User Network Interface (UNI): interfaces are located between protocol User Network Interface (UNI): interfaces are located between protocol
controllers between a user and a control domain. Note: there is no controllers between a user and a control domain. Note: there is no
routing function associated with a UNI reference point. routing function associated with a UNI reference point.
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Appendix 2: ASON Routing Terminology Appendix 2: ASON Routing Terminology
This document makes use of the following terms: This document makes use of the following terms:
Routing Area (RA): a RA represents a partition of the data plane and Routing Area (RA): a RA represents a partition of the data plane and
its identifier is used within the control plane as the representation its identifier is used within the control plane as the representation
of this partition. Per [G.8080] a RA is defined by a set of sub- of this partition. Per [G.8080] a RA is defined by a set of sub-
networks, the links that interconnect them, and the interfaces networks, the links that interconnect them, and the interfaces
representing the ends of the links exiting that RA. A RA may contain representing the ends of the links exiting that RA. A RA may contain
smaller RAs inter-connected by links. The limit of subdivision smaller RAs inter-connected by links. The limit of subdivision
skipping to change at line 949 skipping to change at page 23, line 5
Link Resource Manager (LRM): supplies all the relevant component and Link Resource Manager (LRM): supplies all the relevant component and
TE link information to the RC. It informs the RC about any state TE link information to the RC. It informs the RC about any state
changes of the link resources it controls. changes of the link resources it controls.
Protocol Controller (PC): handles protocol specific message exchanges Protocol Controller (PC): handles protocol specific message exchanges
according to the reference point over which the information is according to the reference point over which the information is
exchanged (e.g. E-NNI, I-NNI), and internal exchanges with the RC. exchanged (e.g. E-NNI, I-NNI), and internal exchanges with the RC.
The PC function is protocol dependent. The PC function is protocol dependent.
D.Papadimitriou et al. - Expires September 2007 19
Full Copyright Statement Full Copyright Statement
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D.Papadimitriou et al. - Expires September 2007 20
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