CCAMP Working Group D. Dhody
Internet-Draft U. Palle
Intended status: Experimental V. Kondreddy
Expires: April 6, 2013 Huawei Technologies India Pvt
Ltd
R. Casellas
CTTC - Centre Tecnologic de
Telecomunicacions de Catalunya
October 3, 2012
Domain Subobjects for Resource ReserVation Protocol - Traffic
Engineering (RSVP-TE)
draft-dhody-ccamp-rsvp-te-domain-subobjects-00
Abstract
The RSVP-TE specification, [RFC3209] and GMPLS extensions to RSVP-TE,
[RFC3473] allow abstract nodes and resources to be explicitly
included in a path setup. Further Exclude Routes Extension [RFC4874]
allow abstract nodes and resources to be explicitly excluded in a
path setup.
The use of Autonomous Number (AS) (2-Byte) as an abstract node
representing domain is already defined in [RFC3209] and [RFC4874].
This document specifies new subobjects to include or exclude domains
during path setup where domain is a collection of network elements
within a common sphere of address management or path computational
responsibility such as an IGP area or an Autonomous Systems (4-Byte).
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 6, 2013.
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Copyright Notice
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Subobjects for Domains . . . . . . . . . . . . . . . . . . . . 4
3.1. Domains . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Explicit Route Object (ERO)'s Subobjects . . . . . . . . . 4
3.2.1. Autonomous system . . . . . . . . . . . . . . . . . . 5
3.2.2. IGP Area . . . . . . . . . . . . . . . . . . . . . . . 6
3.2.3. Mode of Operation . . . . . . . . . . . . . . . . . . 7
3.3. Exclude Route Object (XRO)'s Subobjects . . . . . . . . . 7
3.3.1. Autonomous system . . . . . . . . . . . . . . . . . . 8
3.3.2. IGP Area . . . . . . . . . . . . . . . . . . . . . . . 8
3.3.3. Mode of Operation . . . . . . . . . . . . . . . . . . 9
3.4. Explicit Exclusion Route Subobject . . . . . . . . . . . . 9
4. Interaction with Path Computation Element (PCE) . . . . . . . 10
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5.1. New Subobjects . . . . . . . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Normative References . . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . . 11
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1. Introduction
The RSVP-TE specification [RFC3209] and GMPLS extensions [RFC3473]
allow abstract nodes and resources to be explicitly included in a
path setup, using the Explicit Route Object (ERO).
Further RSVP-TE specification [RFC4874] allows abstract nodes or
resources to be excluded from the whole path using the Exclude Route
object (XRO). To exclude certain abstract nodes or resources between
a specific pair of abstract nodes present in an ERO, a subobject
Explicit Exclusion Route Subobject (EXRS) is used.
[RFC3209] already describes the notion of abstract nodes, where an
abstract node is a group of nodes whose internal topology is opaque
to the ingress node of the LSP. It further defines a subobject for
Autonomous Systems (AS) (2-Byte).
This document extends the notion of abstract nodes by adding new
subobjects for IGP Areas and 4-byte AS numbers. These subobjects MAY
be included in Explicit Route Object (ERO), Exclude Route object
(XRO) or Explicit Exclusion Route Subobject (EXRS).
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.
AS: Autonomous System.
Domain: Any collection of network elements within a common sphere of
address management or path computational responsibility. Examples
of domains include Interior Gateway Protocol (IGP) areas and
Autonomous Systems (ASs).
ERO: Explicit Route Object
EXRS: Explicit Exclusion Route Subobject
IGP: Interior Gateway Protocol. Either of the two routing
protocols, Open Shortest Path First (OSPF) or Intermediate System
to Intermediate System (IS-IS).
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IS-IS: Intermediate System to Intermediate System.
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.
PCEP: Path Computation Element Protocol.
RSVP: Resource Reservation Protocol
TE LSP: Traffic Engineering Label Switched Path.
XRO: Exclude Route Object
3. Subobjects for Domains
3.1. Domains
[RFC4726] and [RFC4655] define domain as a separate administrative or
geographic environment within the network. A domain may be further
defined as a zone of routing or computational ability. Under these
definitions a domain might be categorized as an Autonomous System
(AS) or an Interior Gateway Protocol (IGP) area.
3.2. Explicit Route Object (ERO)'s Subobjects
As stated in [RFC3209], an explicit route is a particular path in the
network topology. In addition to the ability to identify specific
nodes along the path, an explicit route can identify a group of nodes
(abstract nodes) that must be traversed along the path.
Some subobjects are defined in [RFC3209], [RFC3473], [RFC3477],
[RFC4874] and [RFC5553] but new subobjects related to domains are
needed.
The following subobject types are used in ERO.
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Type Subobject
1 IPv4 prefix
2 IPv6 prefix
3 Label
4 Unnumbered Interface ID
32 Autonomous system number (2 Byte)
33 Explicit Exclusion (EXRS)
34 SRLG
64 IPv4 Path Key
65 IPv6 Path Key
This document extends the above list to support 4-Byte AS numbers and
IGP Areas.
Type Subobject
TBD Autonomous system number (4 Byte)
TBD OSPF Area id
TBD ISIS Area id
3.2.1. Autonomous system
[RFC3209] already defines 2-Byte AS number.
To support 4-Byte AS number as per [RFC4893] following subobject is
defined:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AS Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
L: The L bit is an attribute of the subobject as define in [RFC3209].
Type: (TBA by IANA) indicating a 4-Byte AS Number.
Length: 8 (Total length of the subobject in bytes).
Reserved: Zero at transmission, Ignored at receipt.
AS-ID: The 4-Byte AS Number. Note that if 2-Byte AS numbers are in
use, the low order bits (16 through 31) should be used and the high
order bits (0 through 15) should be set to zero.
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3.2.2. IGP Area
Since the length and format of Area-id is different for OSPF and
ISIS, the following two subobjects are defined:
For OSPF, the area-id is a 32 bit number. The subobject is encoded
as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OSPF Area Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
L: The L bit is an attribute of the subobject as define in [RFC3209].
Type: (TBA by IANA) indicating 4-Byte OSPF Area ID.
Length: 8 (Total length of the subobject in bytes).
Reserved: Zero at transmission, Ignored at receipt.
OSPF Area Id: The 4-Byte OSPF Area ID.
For IS-IS, the area-id is of variable length and thus the length of
the subobject is variable. The Area-id is as described in IS-IS by
ISO standard [ISO 10589]. The subobject is encoded as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | Area-Len | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// IS-IS Area ID //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
L: The L bit is an attribute of the subobject as define in [RFC3209].
Type: (TBA by IANA) indicating IS-IS Area ID.
Length: Variable (Total length of the subobject in bytes including
padding). The Length MUST be at least 4, and MUST be a multiple of
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4.
Area-Len: Variable (Length of the actual (non-padded) IS-IS Area
Identifier in bytes; Valid values are from 2 to 11 inclusive).
Reserved: Zero at transmission, Ignored at receipt.
IS-IS Area Id: The variable-length IS-IS area identifier. Padded
with trailing zeroes to a four-byte boundary.
3.2.3. Mode of Operation
The new subobjects to support 4-Byte AS and IGP (OSPF / ISIS) Area
MAY also be used in the ERO to specify an abstract node (a group of
nodes whose internal topology is opaque to the ingress node of the
LSP).
All the rules of processing (for example Next Hop Selection, L bit
processing, unrecognized subobjects etc) are as per the [RFC3209].
3.3. Exclude Route Object (XRO)'s Subobjects
As stated in [RFC4874], the exclude route identifies a list of
abstract nodes that should not be traversed along the path of the LSP
being established.
Some subobjects are defined in [RFC3209], [RFC3477], [RFC4874] and
[RFC6001] but new subobjects related to domains are needed.
The following subobject types are used in XRO.
Type Subobject
1 IPv4 prefix
2 IPv6 prefix
3 Label
4 Unnumbered Interface ID
32 Autonomous system number (2 Byte)
34 SRLG
This document extends the above list to support 4-Byte AS numbers and
IGP Areas.
Type Subobject
TBD Autonomous system number (4 Byte)
TBD OSPF Area id
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TBD ISIS Area id
3.3.1. Autonomous system
[RFC3209] and and [RFC4874] already defines a 2-Byte AS number.
To support 4-Byte AS number as per [RFC4893], the following subobject
is defined:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AS Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The meaning of the L bit, similar to [RFC4874], is as follows:
0 indicates that the abstract node (AS) specified MUST be excluded.
1 indicates that the abstract node (AS) specified SHOULD be avoided.
The meaning of all the other elements (Type, Length, Reserved and
4-Byte AS Id) is same as explained above in Section 3.2.1.
3.3.2. IGP Area
Since the length and format of Area-id is different for OSPF and
ISIS, following two subobjects are defined:
For OSPF, the area-id is a 32 bit number. The subobject is encoded
as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OSPF Area Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The meaning of the L bit, similar to [RFC4874], is as follows:
0 indicates that the abstract node (OSPF Area) specified MUST be
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excluded.
1 indicates that the abstract node (OSPF Area) specified SHOULD be
avoided.
The meaning of all the other elements (Type, Length, Reserved and
OSPF Area Id) is same as explained above in Section 3.2.2.
For IS-IS, the area-id is of variable length and thus the length of
the subobject is variable. The Area-id is as described in IS-IS by
ISO standard [ISO 10589]. The subobject is encoded as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | Area-Len | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// IS-IS Area ID //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The meaning of the L bit, similar to [RFC4874], is as follows:
0 indicates that the abstract node (IS-IS Area) specified MUST be
excluded.
1 indicates that the abstract node (IS-IS Area) specified SHOULD be
avoided.
The meaning of all the other elements (Type, Length, Reserved and
IS-IS Area Id) is same as explained above in Section 3.2.2.
3.3.3. Mode of Operation
The new subobjects to support 4-Byte AS and IGP (OSPF / ISIS) Area
MAY also be used in the XRO to specify exclusion of an abstract node
(a group of nodes whose internal topology is opaque to the ingress
node of the LSP).
All the rules of processing are as per the [RFC4874].
3.4. Explicit Exclusion Route Subobject
As stated in [RFC4874], the Explicit Exclusion Route defines abstract
nodes or resources that must not or should not be used on the path
between two inclusive abstract nodes or resources in the explicit
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route. EXRS is an ERO subobject that contains one or more subobjects
of its own, called EXRS subobjects.
The EXRS subobject may carry any of the subobjects defined for XRO,
thus the new subobjects to support 4-Byte AS and IGP (OSPF / ISIS)
Area MAY also be used in the EXRS. The meanings of the fields of the
new XRO subobjects are unchanged when the subobjects are included in
an EXRS, except that scope of the exclusion is limited to the single
hop between the previous and subsequent elements in the ERO.
All the rules of processing are as per the [RFC4874].
4. Interaction with Path Computation Element (PCE)
The domain subobjects to be used in Path Computation Element Protocol
(PCEP) are referred to in [PCE-DOMAIN]. Note that the new domain
subobjects follow the principle that subobjects used in PCEP
[RFC5440] are identical to the subobjects used in RSVP-TE.
5. IANA Considerations
5.1. New Subobjects
IANA registry: RSVP PARAMETERS
Subsection: Class Names, Class Numbers, and Class Types
IANA is requested to add further subobjects to the existing entry
for:
20 EXPLICIT_ROUTE
232 EXCLUDE_ROUTE
Subobject Type Reference
TBA 4-Byte AS number [This I.D.]
TBA OSPF Area ID [This I.D.]
TBA IS-IS Area ID [This I.D.]
6. Security Considerations
Security considerations for MPLS-TE and GMPLS signaling are covered
in [RFC3209] and [RFC3473]. This document does not introduce any new
messages or any substantive new processing, and so those security
considerations continue to apply.
The route exclusion security consideration are covered in [RFC4874]
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and continue to apply.
7. Acknowledgments
We would like to thank Reeja Paul and Sandeep Boina for their useful
comments and suggestions.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
8.2. Informative References
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
V., and G. Swallow, "RSVP-TE: Extensions to RSVP for
LSP Tunnels", RFC 3209, December 2001.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473,
January 2003.
[RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered
Links in Resource ReSerVation Protocol - Traffic
Engineering (RSVP-TE)", RFC 3477, January 2003.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path
Computation Element (PCE)-Based Architecture",
RFC 4655, August 2006.
[RFC4726] Farrel, A., Vasseur, J., and A. Ayyangar, "A Framework
for Inter-Domain Multiprotocol Label Switching Traffic
Engineering", RFC 4726, November 2006.
[RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude
Routes - Extension to Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE)", RFC 4874, April 2007.
[RFC4893] Vohra, Q. and E. Chen, "BGP Support for Four-octet AS
Number Space", RFC 4893, May 2007.
[RFC5440] Vasseur, JP. and JL. Le Roux, "Path Computation Element
(PCE) Communication Protocol (PCEP)", RFC 5440,
March 2009.
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[RFC5553] Farrel, A., Bradford, R., and JP. Vasseur, "Resource
Reservation Protocol (RSVP) Extensions for Path Key
Support", RFC 5553, May 2009.
[RFC6001] Papadimitriou, D., Vigoureux, M., Shiomoto, K.,
Brungard, D., and JL. Le Roux, "Generalized MPLS
(GMPLS) Protocol Extensions for Multi-Layer and Multi-
Region Networks (MLN/MRN)", RFC 6001, October 2010.
[PCE-DOMAIN] Dhody, D., Palle, U., and R. Casellas, "Standard
Representation Of Domain Sequence.
(draft-ietf-pce-pcep-domain-sequence-01)", July 2012.
[ISO 10589] ISO, "Intermediate system to Intermediate system
routeing information exchange protocol for use in
conjunction with the Protocol for providing the
Connectionless-mode Network Service (ISO 8473)", ISO/
IEC 10589:2002.
Authors' Addresses
Dhruv Dhody
Huawei Technologies India Pvt Ltd
Leela Palace
Bangalore, Karnataka 560008
INDIA
EMail: dhruv.dhody@huawei.com
Udayasree Palle
Huawei Technologies India Pvt Ltd
Leela Palace
Bangalore, Karnataka 560008
INDIA
EMail: udayasree.palle@huawei.com
Venugopal Reddy Kondreddy
Huawei Technologies India Pvt Ltd
Leela Palace
Bangalore, Karnataka 560008
INDIA
EMail: venugopalreddyk@huawei.com
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Ramon Casellas
CTTC - Centre Tecnologic de Telecomunicacions de Catalunya
Av. Carl Friedrich Gauss n7
Castelldefels, Barcelona 08860
SPAIN
EMail: ramon.casellas@cttc.es
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