RSVP-TE Extensions for Associated Bidirectional LSPs
draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-08
CCAMP Working Group F. Zhang, Ed.
Internet-Draft ZTE
Intended status: Standards Track R. Jing
Expires: September 3, 2014 China Telecom
R. Gandhi, Ed.
Cisco Systems
March 2, 2014
RSVP-TE Extensions for Associated Bidirectional LSPs
draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-08
Abstract
This document describes Resource reSerVation Protocol (RSVP)
extensions to bind two point-to-point unidirectional Label Switched
Paths (LSPs) into an associated bidirectional LSP. The association is
achieved by defining the new Association Types in (Extended)
ASSOCIATION object. In addition, RSVP extensions allow asymmetric
upstream and downstream bandwidths for the bidirectional LSP.
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
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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
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include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions used in this document . . . . . . . . . . . . . . 4
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Provisioning Model Overview . . . . . . . . . . . . . . . 4
3.1.1. Single Sided Provisioning . . . . . . . . . . . . . . 4
3.1.2. Double Sided Provisioning . . . . . . . . . . . . . . 4
3.2. Association Signaling Overview . . . . . . . . . . . . . . 5
3.2.1. Single Sided Provisioning . . . . . . . . . . . . . . 5
3.2.2. Double Sided Provisioning . . . . . . . . . . . . . . 6
3.3. Asymmetric Bandwidth Signaling Overview . . . . . . . . . 6
3.3.1. Single Sided Provisioning . . . . . . . . . . . . . . 6
3.3.2. Double Sided Provisioning . . . . . . . . . . . . . . 6
3.4. Recovery LSP Overview . . . . . . . . . . . . . . . . . . 7
3.4.1. Single Sided Provisioning . . . . . . . . . . . . . . 7
3.4.2. Double Sided Provisioning . . . . . . . . . . . . . . 7
3.5. Provisioning For Mesh-Groups . . . . . . . . . . . . . . . 7
4. Processing Rules . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. ASSOCIATION Object . . . . . . . . . . . . . . . . . . . . 8
4.2. Extended ASSOCIATION Object . . . . . . . . . . . . . . . 8
4.3. Rules For ASSOCIATION Object . . . . . . . . . . . . . . . 9
4.3.1. Teardown of Associated LSPs . . . . . . . . . . . . . 10
4.3.2. Compatibility For ASSOCIATION Object . . . . . . . . . 10
4.4. Rules For REVERSE_LSP Object . . . . . . . . . . . . . . . 10
4.4.1. Teardown of Associated LSPs . . . . . . . . . . . . . 11
4.4.2. Compatibility For REVERSE_LSP Object . . . . . . . . . 11
5. Message and Object Definitions . . . . . . . . . . . . . . . . 12
5.1. RSVP Message Formats . . . . . . . . . . . . . . . . . . . 12
5.2. ASSOCIATION Object Definition . . . . . . . . . . . . . . 12
5.3. REVERSE_LSP Object Definition . . . . . . . . . . . . . . 12
5.3.1. REVERSE_LSP Object Format . . . . . . . . . . . . . . 12
5.3.2. REVERSE_LSP Subobjects . . . . . . . . . . . . . . . . 13
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
6.1. Association Types . . . . . . . . . . . . . . . . . . . . 13
6.2. REVERSE_LSP Object . . . . . . . . . . . . . . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
8. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
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1. Introduction
The MPLS Transport Profile (MPLS-TP) requirements document [RFC5654]
specifies that MPLS-TP MUST support associated bidirectional point-
to-point Label Switched Paths (LSPs). These requirements are given in
Section 2.1 (General Requirements), and are repeated below:
7. MPLS-TP MUST support associated bidirectional point-to-point
LSPs.
11. The end points of an associated bidirectional LSP MUST be aware
of the pairing relationship of the forward and reverse LSPs used to
support the bidirectional service.
12. Nodes on the LSP of an associated bidirectional LSP where both
the forward and backward directions transit the same node in the same
(sub)layer as the LSP SHOULD be aware of the pairing relationship of
the forward and the backward directions of the LSP.
14. MPLS-TP MUST support bidirectional LSPs with asymmetric
bandwidth requirements, i.e., the amount of reserved bandwidth
differs between the forward and backward directions.
50. The MPLS-TP control plane MUST support establishing associated
bidirectional P2P LSP including configuration of protection functions
and any associated maintenance functions.
The above requirements are also repeated in [RFC6373].
Furthermore, an associated bidirectional LSP is also useful for
protection switching for Operations, Administrations and Maintenance
(OAM) messages that require a return path.
A variety of applications, such as Internet services and the return
paths of OAM messages, exist and which may have different upstream
and downstream bandwidth requirements. [RFC5654] specifies an
asymmetric bandwidth requirement in Section 2.1 (General
Requirements), and is repeated below:
14. MPLS-TP MUST support bidirectional LSPs with asymmetric
bandwidth requirements, i.e., the amount of reserved bandwidth
differs between the forward and backward directions.
The approach for supporting asymmetric bandwidth co-routed
bidirectional LSPs is defined in [RFC6387].
The method of association and the corresponding Resource reSerVation
Protocol (RSVP) ASSOCIATION object are defined in [RFC4872],
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[RFC4873] and [RFC6689]. In that context, the ASSOCIATION object is
used to associate a recovery LSP with the LSP it is protecting. This
object also has broader applicability as a mechanism to associate
RSVP states. [RFC6780] defines an Extended ASSOCIATION object that
can be more generally applied for this purpose.
This document specifies mechanisms for binding two reverse
unidirectional LSPs into an associated bidirectional LSP. The
association is achieved by defining new Association Types in the
(Extended) ASSOCIATION object. RSVP extensions allow asymmetric
upstream and downstream bandwidths for the bidirectional LSP.
2. Conventions used in this document
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].
3. Overview
3.1. Provisioning Model Overview
This section provides an overview of the models for provisioning
bidirectional LSPs.
The associated bidirectional LSP's forward and reverse unidirectional
LSPs are established, monitored, and protected independently as
specified by [RFC5654]. Configuration information regarding the LSPs
can be provided at one or both endpoints of the associated
bidirectional LSP. Depending on the method chosen, there are two
models of creating an associated bidirectional LSP; single sided
provisioning, and double sided provisioning.
3.1.1. Single Sided Provisioning
For the single sided provisioning, the TE tunnel is configured only
on one side. An LSP for this tunnel is initiated by the initiating
endpoint with the (Extended) ASSOCIATION object inserted in the Path
message. The other endpoint then creates the corresponding reverse TE
tunnel and signals the reverse LSP in response to this.
3.1.2. Double Sided Provisioning
For the double sided provisioning, two unidirectional TE tunnels are
configured independently on both sides. The LSPs for the tunnels are
signaled with (Extended) ASSOCIATION objects inserted in the Path
message by both sides to indicate that the two LSPs are to be
associated to form a bidirectional LSP.
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3.2. Association Signaling Overview
This section provides an overview of the association signaling
methods for the bidirectional LSPs.
Three scenarios exist for binding two unidirectional LSPs together to
form an associated bidirectional LSP. These are: 1) Neither
unidirectional LSP exists, and both must be established. 2) Both
unidirectional LSPs exist, but the association must be established.
3) One LSP exists, but the reverse associated LSP must be
established.
In each of the situations described above, both provisioning models
are applicable.
Path Computation Element (PCE)-based approaches [RFC4655], may be
used for path computation of an associated bidirectional LSP.
However, these approaches are outside the scope of this document.
Consider the topology described in Figure 1 (an example of associated
bidirectional LSP). LSP1 from A to B, takes the path A,D,B and LSP2
from B to A takes the path B,D,C,A. These two LSPs, once established
and associated, form an associated bidirectional LSP between node A
and node B.
LSP1 -->
A-------D-------B
\ / <-- LSP2
\ /
\ /
C
Figure 1: An example of associated bidirectional LSP
3.2.1. Single Sided Provisioning
For the single sided provisioning model, creation of reverse LSP1 is
triggered by LSP2 or creation of reverse LSP2 is triggered by LSP1.
When creation of reverse LSP2 is triggered by LSP1, LSP1 is
provisioned first (or refreshed if LSP1 already exists) at node A.
LSP1 is then signaled with an (Extended) ASSOCIATION object inserted
in the Path message, in which the Association Type indicating single
sided provisioning. Upon receiving this Path message for LSP1, node B
establishes reverse LSP2. The (Extended) ASSOCIATION object inserted
in LSP2's Path message is the same as that received in LSP1's Path
message.
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A similar procedure is used if LSP2 is provisioned first at node B
and the creation of reverse LSP1 is triggered by LSP2. In both cases,
the two unidirectional LSPs are bound together to form an associated
bidirectional LSP based on identical (Extended) ASSOCIATION objects
in the two LSPs' Path messages.
3.2.2. Double Sided Provisioning
For the double sided provisioning model, both LSP1 and LSP2 are
signaled independently with (Extended) ASSOCIATION object inserted in
the Path message, in which the Association Type indicating double
sided provisioning. In this case, the two unidirectional LSPs are
bound together to form an associated bidirectional LSP based on
identical (Extended) ASSOCIATION objects in the two LSPs' Path
messages.
3.3. Asymmetric Bandwidth Signaling Overview
This section provides an overview of the methods for signaling
asymmetric upstream and downstream bandwidths for the associated
bidirectional LSPs.
3.3.1. Single Sided Provisioning
New REVERSE_LSP object applicable to the single sided provisioning
model is defined in this document, in Section 5.3. When the single
sided provisioning model is used, the existing SENDER_TSPEC object is
added in the REVERSE_LSP object as a subobject in the initiating
LSP's Path message to specify the reverse LSP's traffic parameters.
As described in Section 5.3, addition of the REVERSE_LSP object also
allows the initiating node to control the reverse LSP.
Consider again the topology described in Figure 1, where the creation
of reverse LSP2 is triggered by LSP1. Node A signals LSP1 with the
(Extended) ASSOCIATION object with Association Type indicating single
sided provisioning and inserts SENDER_TSPEC subobject in the
REVERSE_LSP object in the Path message. Node B then establishes the
LSP2 in the reverse direction using the asymmetric bandwidth thus
specified by LSP1 and allows node A to control the reverse LSP2.
3.3.2. Double Sided Provisioning
When the double sided provisioning model is used, the two
unidirectional LSPs are established with asymmetric bandwidths
independently. However, these LSPs are associated purely based on the
identical contents of their (Extended) ASSOCIATION objects.
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3.4. Recovery LSP Overview
Consider again the topology described in Figure 1, where LSP1 and
LSP2 form an associated bidirectional LSP. Under a recovery scenario,
a third LSP (LSP3) may be used to protect LSP1 on node A. LSP3 may be
established before or after the failure occurs. LSP3 in this case
belongs to the same TE tunnel as LSP1 on node A.
When node A detects that LSP1 has failed or needs to be reoptimized,
LSP3 is initialized or refreshed with the (Extended) ASSOCIATION
object (including the Association Type) inherited from LSP1's Path
message. If LSP3 is the protecting LSP [RFC4872], the PROTECTION
object [RFC4872] is also inherited from LSP1. In any case, LSP2 and
LSP3 are associated to form an associated bidirectional LSP based on
the identical (Extended) ASSOCIATION objects in their Path messages.
3.4.1. Single Sided Provisioning
When the single sided provisioning model is used, recovery LSP3 on
node A triggers the creation of reverse recovery LSP4 on node B as
described in Section 3.2.1 of this document. However, node A and node
B perform LSP recovery actions independently [RFC5654].
3.4.2. Double Sided Provisioning
When the double sided provisioning model is used, recovery LSP3 on
node A may or may not have associated reverse recovery LSP4 on node
B. In any case, node A and node B perform LSP recovery actions
independently [RFC5654].
3.5. Provisioning For Mesh-Groups
TE mesh-groups are defined in [RFC4972]. In order to enable
unambiguous association of the mesh-group's bidirectional LSPs, the
information carried in the (Extended) ASSOCIATION object,
specifically the contents of the Association Source and Identifier
fields are provisioned for the mesh-groups using the models specified
in Section 3.1.1 and 3.1.2 of this document, namely, single sided and
double sided provisioning.
4. Processing Rules
In general, the processing rules for the ASSOCIATION object are as
specified in [RFC4872] and Extended ASSOCIATION object are specified
in [RFC6780]. Following sections describe the rules for processing
(Extended) ASSOCIATION and REVERSE_LSP objects for associated
bidirectional LSPs.
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4.1. ASSOCIATION Object
The ASSOCIATION object is populated using the rules defined below for
associating two reverse unidirectional LSPs to form a bidirectional
LSP.
Association Types:
In order to bind two reverse unidirectional LSPs to be an
associated bidirectional LSP, the Association Type MUST be set to
indicate either single sided or double sided LSPs.
The new Association Types are defined as follows:
Value Type
----- -----
4 (TBD) Double Sided Associated Bidirectional LSPs (D)
5 (TBD) Single Sided Associated Bidirectional LSPs (A)
Association ID:
For both single sided and double sided provisioning, Association
ID MUST be set to a value assigned by the node that originates the
association for the bidirectional LSP.
Association Source:
For double sided provisioning, Association Source MUST be set to
an address selected by the node that originates the association
for the bidirectional LSP (which may be a management entity.)
For single sided provisioning, Association Source MUST be set to
an address assigned to the node that originates the LSP.
4.2. Extended ASSOCIATION Object
The Extended ASSOCIATION object is populated using the rules defined
below for associating two reverse unidirectional LSPs to form a
bidirectional LSP.
The Association Type, Association ID and Association Source MUST be
set as defined for the ASSOCIATION object in Section 4.1.
Global Association Source:
For both single sided and double sided provisioning, Global
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Association Source, when used, MUST be set to the Global_ID
[RFC6370] of the node that originates the association for the
bidirectional LSP.
Extended Association ID:
For both single sided and double sided provisioning, Extended
Association ID, when used, MUST be set to a value selected by the
node that originates the association for the bidirectional LSP.
4.3. Rules For ASSOCIATION Object
The ASSOCIATION object is inserted in the Path message of the LSP
using the rules defined in this document for associating two reverse
unidirectional LSPs to form an associated bidirectional LSP.
For associating two unidirectional LSPs to form a bidirectional LSP,
if either Global Association Source or Extended Association Address
is required, then an Extended ASSOCIATION object [RFC6780] is
inserted in the Path message of the LSP instead of the ASSOCIATION
object.
Association Type in the (Extended) ASSOCIATION object MUST be set to
the "Single Sided Associated Bidirectional LSPs" or "Double Sided
Associated Bidirectional LSPs" based on the single sided or double
sided provisioning model used for the LSPs. ASSOCIATION or Extended
ASSOCIATION objects with both single sided and double sided
Association Types MUST NOT be added in the same Path message.
As described in [RFC6780], association of the LSPs is based on
matching ASSOCIATION objects in Path or Resv. Upstream initialized
association is represented in (Extended) ASSOCIATION object carried
in the Path message and downstream initialized association is
represented in (Extended) ASSOCIATION object carried in the Resv
message. The new Association Types defined in this document are only
used in upstream initialized association. Thus they can appear in the
(Extended) ASSOCIATION object in Path message only.
The procedures associated with the processing of the (Extended)
ASSOCIATION objects are discussed in [RFC6780]. [RFC6780] specifies
that in the absence of Association Type-specific rule for identifying
association, the included (Extended) ASSOCIATION objects in the LSPs
MUST be identical in order for an association to be formed. This
document adds no specific rules for the new Association Types
defined, and the determination of LSP association therefore proceeds
as specified in [RFC6780].
LSP recovery as defined in [RFC4872] and [RFC4873] is not impacted by
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this document. The recovery mechanisms defined in [RFC4872] and
[RFC4873] rely on the use of ASSOCIATION objects, but use a different
value for Association Type; multiple ASSOCIATION objects MAY exist in
the LSP Path message and MAY coexist with the procedures defined in
this document.
As specified in [RFC4872], an endpoint node that does not support the
new Association Types defined in this document MUST return a PathErr
message with the error code "LSP Admission Failure" (value 01 as
defined in [RFC2205]) and the sub-code "Bad Association Type" (value
5 as defined in [RFC4872]).
4.3.1. Teardown of Associated LSPs
Associated bidirectional LSP teardown follows the standard procedures
defined in [RFC3209] and [RFC3473] either without or with the
administrative status. Note that teardown procedures of the
unidirectional LSPs forming an associated bidirectional LSP are
independent of each other, so it is possible that while one LSP
follows graceful teardown with administrative status, the reverse LSP
is torn down without administrative status (using
PathTear/ResvTear/PathErr with state removal).
For the single sided provisioning where the REVERSE_LSP object is not
signaled, the teardown of the initiating LSP SHOULD trigger the
teardown of the reverse LSP, however, teardown of the reverse LSP MAY
NOT trigger the teardown of the initiating LSP (which may depend on
the local policy).
For the double sided provisioning, the teardown of one unidirectional
LSP SHOULD not trigger teardown of the reverse LSP.
4.3.2. Compatibility For ASSOCIATION Object
The ASSOCIATION object has been defined in [RFC4872] and the Extended
ASSOCIATION object has been defined in [RFC6780], both with class
numbers in the form 11bbbbbb, which ensures compatibility with
non-supporting nodes. Per [RFC2205], such nodes will ignore the
object but forward it without modification.
Operators wishing to use a function supported by a particular
association type SHOULD ensure that the type is supported on any node
that is expected to act on the association [RFC6780].
4.4. Rules For REVERSE_LSP Object
A node initiating a Path message containing an ASSOCIATION or
Extended ASSOCIATION object with the Association Type set to "Single
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Sided Associated Bidirectional LSPs" MAY include a REVERSE_LSP object
in the Path message of the LSP when it wishes to control the reverse
LSP on the other endpoint node and to specify the reverse LSP's
traffic parameters.
The REVERSE_LSP subobject MAY contain any of the specified subobjects
which the initiating node desires to have included in the Path
message for the associated reverse LSP. A REVERSE_LSP object MUST
contain at least one subobject.
A node receiving a valid Path message containing a REVERSE_LSP object
that is not the endpoint node for the LSP being signaled MUST forward
the REVERSE_LSP object unchanged in the outgoing Path message.
The endpoint node upon receiving a Path message containing a
REVERSE_LSP object triggers to establish the reverse LSP according to
the received parameters in the REVERSE_LSP object. The receiver
endpoint node MUST convert the subobjects of the REVERSE_LSP object
into the corresponding objects to be carried in the reverse LSP's
Path message.
A Path message that does not contain an ASSOCIATION or Extended
ASSOCIATION object with the Association Type set to "Single Sided
Associated Bidirectional LSPs" MUST NOT contain a REVERSE_LSP object.
4.4.1. Teardown of Associated LSPs
If initiating node controlling the reverse LSP using the procedure
defined in this document, wishes to tear down the associated
bidirectional LSP, the initiating node sends a PathTear message to
the other endpoint, the other endpoint MUST trigger to tear down the
reverse associated LSP.
4.4.2. Compatibility For REVERSE_LSP Object
The REVERSE_LSP object is defined with class numbers in the form
11bbbbbb, which ensures compatibility with non-supporting nodes. Per
[RFC2205], such nodes will ignore the object but forward it without
modification.
Per [RFC2205], an endpoint node that does not support the REVERSE_LSP
C-Type MAY generate an "Unknown object C-Type" error. This error will
propagate to the initiating node for standard error processing.
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5. Message and Object Definitions
5.1. RSVP Message Formats
This section presents the RSVP message-related formats as modified by
this document. Unmodified RSVP message formats are not listed.
The format of a Path message is as follows:
<Path Message> ::= <Common Header> [ <INTEGRITY> ]
[ [<MESSAGE_ID_ACK> | <MESSAGE_ID_NACK>] ... ]
[ <MESSAGE_ID> ]
<SESSION> <RSVP_HOP>
<TIME_VALUES>
[ <EXPLICIT_ROUTE> ]
<LABEL_REQUEST>
[ <PROTECTION> ]
[ <LABEL_SET> ... ]
[ <SESSION_ATTRIBUTE> ]
[ <NOTIFY_REQUEST> ... ]
[ <ADMIN_STATUS> ]
[ <ASSOCIATION> ... ]
[ <REVERSE_LSP]
[ <POLICY_DATA> ... ]
<sender descriptor>
The format of the <sender descriptor> is not modified by this
document.
5.2. ASSOCIATION Object Definition
The ASSOCIATION object is defined in [RFC4872]. The Extended
ASSOCIATION object is defined in [RFC6780]. Other than the two new
Association Types defined in this document, the (Extended)
ASSOCIATION object definition is not modified by this document.
5.3. REVERSE_LSP Object Definition
5.3.1. REVERSE_LSP Object Format
The information of the reverse LSP is specified via the REVERSE_LSP
object. This is an optional object carried in a Path message with
class numbers in the form 11bbbbbb and has the following format:
Class = TBD (of the form 11bbbbbb), C_Type = (TBD)
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// (Subobjects) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
5.3.2. REVERSE_LSP Subobjects
The contents of a REVERSE_LSP object is a variable length series of
subobjects. The subobjects permitted in the REVERSE_LSP object are
previously defined as Path message subobjects, and have the same
format and order in the REVERSE_LSP object.
Examples of the Path message subobjects carried in the REVERSE_LSP
object are (but not limited to):
- SENDER_TSPEC [RFC2205]
- EXPLICIT_ROUTE object (ERO) [RFC3209]
- SESSION_ATTRIBUTE object [RFC3209]
- ADMIN_STATUS object [RFC3473]
- LSP_ATTRIBUTES object [RFC5420]
- LSP_REQUIRED_ATTRIBUTES object [RFC5420]
- PROTECTION object [RFC3473] [RFC4872]
6. IANA Considerations
IANA is requested to administer assignment of new values for
namespace defined in this document and summarized in this section.
6.1. Association Types
New Association Types for ASSOCIATION and Extended ASSOCIATION
objects are defined in this document as follows:
Value Type
----- -----
4 (TBD) Double Sided Associated Bidirectional LSPs (D)
5 (TBD) Single Sided Associated Bidirectional LSPs (A)
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6.2. REVERSE_LSP Object
A new class type for REVERSE_LSP has been requested in the 11bbbbbb
range (TBD) with the following definition:
Class Types or C-types (TBD), Value (TBD): REVERSE_LSP Object
There are no other IANA considerations introduced by this document.
7. Security Considerations
This document introduces two new Association Types, however, no new
security issues relating to the (Extended) ASSOCIATION object are
introduced.
The procedures defined in this document result in an increased state
information carried in signaling messages. The presence of the
REVERSE_LSP object necessarily provides more information about the
LSPs. Thus, in the event of the interception of a signaling message,
slightly more information about the state of the network could be
deduced than was previously the case. This is judged to be a very
minor security risk as this information is already available via
routing.
Otherwise, this document introduces no additional security
considerations. For a general discussion on MPLS and GMPLS related
security issues, see the MPLS/GMPLS security framework [RFC5920].
8. Acknowledgement
The authors would like to thank Lou Berger and George Swallow for
their great guidance in this work, Jie Dong for the discussion of
recovery, Lamberto Sterling for his valuable comments on the section
of asymmetric bandwidths, Daniel King for the review of the document,
Attila Takacs for the discussion of the provisioning model. At the
same time, the authors would also like to acknowledge the
contributions of Bo Wu, Xihua Fu, Lizhong Jin for the initial
discussions, and Wenjuan He for the prototype implementation. The
authors would also like to thank Siva Sivabalan, Eric Osborne and
Robert Sawaya for the discussions on the ASSOCIATION object. The
authors would like to thank Matt Hartley for providing useful
suggestions on the document.
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9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S.
Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
Functional Specification", RFC 2205, September 1997.
[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.
[RFC4872] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE
Extensions in Support of End-to-End Generalized Multi-
Protocol Label Switching (GMPLS) Recovery", RFC 4872, May
2007.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
"GMPLS Segment Recovery", RFC 4873, May 2007.
[RFC6780] Berger, L., Le Faucheur, F., and A. Narayanan, "RSVP
Association Object Extensions", RFC 6780, October 2012.
9.2. Informative References
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC4972] Vasseur, JP., Leroux, JL., Yasukawa, S., Previdi, S.,
Psenak, P., Mabbey, P., "Routing Extensions for Discovery
of Multiprotocol (MPLS) Label Switch Router (LSR) Traffic
Engineering (TE) Mesh Membership", RFC 4972, July 2007.
[RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N.,
and S. Ueno, "Requirements of an MPLS Transport Profile",
RFC 5654, September 2009.
[RFC5920] Fang, L., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010.
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[RFC6370] Bocci, M., Swallow, G., and E. Gray, "MPLS Transport
Profile (MPLS-TP) Identifiers", RFC 6370, September 2011.
[RFC6373] Andersson, L., Berger, L., Fang, L., Bitar, N., and E.
Gray, "MPLS Transport Profile (MPLS-TP) Control Plane
Framework", RFC 6373, September 2011.
[RFC6387] Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J.
Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label
Switched Paths (LSPs)", RFC 6387, September 2011.
[RFC6689] Berger, L., "Usage of The RSVP Association Object", RFC
6689, July 2012.
Authors' Addresses
Fei Zhang (editor)
ZTE
Email: zhang.fei3@zte.com.cn
Ruiquan Jing
China Telecom
Email: jingrq@ctbri.com.cn
Fan Yang
ZTE
Email: yang.fan240347@gmail.com
Weilian Jiang
ZTE
Email: jiang.weilian@gmail.com
Rakesh Gandhi (editor)
Cisco Systems
Email: rgandhi@cisco.com
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