One document matched: draft-zhang-ccamp-gmpls-resource-sharing-proc-02.txt
Differences from draft-zhang-ccamp-gmpls-resource-sharing-proc-01.txt
CCAMP Working Group Xian Zhang
Internet Draft Haomian Zheng, Ed.
Intended Status: Informational Huawei
Rakesh Gandhi, Ed.
Zafar Ali
Gabriele Maria Galimberti
Cisco Systems, Inc.
Pawel Brzozowski
ADVA Optical
Expires: March 12, 2015 September 12, 2014
RSVP-TE Signaling Procedure for GMPLS Restoration and Resource Sharing-
based LSP Setup/Teardown
draft-zhang-ccamp-gmpls-resource-sharing-proc-02
Abstract
In transport networks, there are requirements where Generalized
Multi-Protocol Label Switching (GMPLS) end-to-end recovery scheme
needs to employ restoration Label Switched Path (LSP) while keeping
resources for the working and/or restoration LSPs reserved in the
network after the failure occurs.
This document reviews how the LSP association is to be provided using
Resource Reservation Protocol - Traffic Engineering (RSVP-TE)
signaling in the context of GMPLS end-to-end recovery when using
restoration LSP where failed LSP is not torn down. In addition, this
document compliments existing standards by explaining the missing
pieces of information during the RSVP-TE signaling procedure in
support of resource sharing-based LSP setup/teardown in GMPLS-
controlled circuit networks. No new procedures or mechanisms are
defined by this document, and it is strictly informative in nature.
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with
the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on March 12th, 2015.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents carefully,
as they describe your rights and restrictions with respect to this
document. Code Components extracted from this document must include
Simplified BSD License text as described in Section 4.e of the Trust
Legal Provisions and are provided without warranty as described in
the Simplified BSD License.
Table of Contents
1. Introduction ................................................ 3
2. Problem Statement ........................................... 4
2.1. GMPLS Restoration ....................................... 5
2.1.1. 1+R Restoration .................................... 5
2.1.2. 1+1+R Restoration .................................. 5
2.2. Resource Sharing-based LSP Setup/Teardown ............... 6
3. RSVP-TE Signaling For Restoration LSP Association ............ 7
4. RSVP-TE Signaling Procedure For Resource Sharing During LSP
Setup/Teardown ................................................. 8
4.1. LSPs with the Identical Tunnel ID ....................... 8
4.1.1. LSP Setup ......................................... 9
4.1.2. LSP Reversion ..................................... 11
4.1.3. LSP Re-optimization Setup and Reversion ........... 13
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4.2. LSPs with Different Tunnel IDs ......................... 13
5. Security Considerations ..................................... 14
6. IANA Considerations ........................................ 14
7. Acknowledgement ............................................ 14
8. References ................................................. 14
8.1. Normative References ................................... 14
8.2. Informative References ................................. 15
9. Authors' Addresses ......................................... 16
1. Introduction
Generalized Multiprotocol Label Switching (GMPLS) [RFC3945] defines a
set of protocols, including Open Shortest Path First - Traffic
Engineering (OSPF-TE) [RFC4203] and Resource ReserVation Protocol -
Traffic Engineering (RSVP-TE) [RFC3473]. These protocols can be used
to create Label Switched Paths (LSPs) in a number of deployment
scenarios with various transport technologies. The GMPLS protocol
set extends MPLS, which supports only Packet Switch Capable (PSC) and
Layer 2 Switch Capable interfaces (L2SC), to also cater for
interfaces capable of Time Division Multiplexing (TDM), Lambda
Switching and Fiber Switching. These switching technologies provide
several protection schemes [RFC4426][RFC4427] (e.g., 1+1, 1:N and
M:N). Resource Reservation Protocol - Traffic Engineering (RSVP-TE)
signaling has been extended to support various GMPLS recovery schemes
[RFC4872][RFC4873], to establish Label Switched Paths (LSPs),
typically for working LSP and protecting LSP. [RFC4427] Section 7
specifies various schemes for GMPLS recovery.
In GMPLS recovery schemes generally considered, restoration LSP is
signaled after the failure has been detected and notified on the
working LSP. In non-revertive recovery mode, working LSP is assumed
to be removed from the network before restoration LSP is signaled.
For revertive recovery mode, a restoration LSP is signaled while
working LSP and/or protecting LSP are not torn down in control plane
due to a failure. In transport networks, as working LSPs are
typically signaled over a nominal path, service providers would like
to keep resources associated with the working LSPs reserved. This is
to make sure that the service (working LSP) can use the nominal path
when the failure is repaired to provide deterministic behaviour and
guaranteed Service Level Agreement (SLA). Consequently, revertive
recovery mode is usually preferred by recovery schemes used in
transport networks.
The Make-Before-Break (MBB) exploiting the Shared-Explicit (SE)
reservation style can be employed in MPLS networks to avoid double
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booking of resource during the process of LSP reoptimization as
specified in [RFC3209]. This method is also used in GMPLS-controlled
networks [RFC4872] [RFC4873] for end-to-end and segment recoveries of
LSPs. This was further generalized to support resource sharing
oriented applications in MPLS networks as well as non-LSP contexts,
as specified in [RFC6780].
Due to the fact that the features of GMPLS-controlled networks
(specifically for TDM, LSC and FSC), are not identical to that of the
MPLS networks, additional considerations for resource sharing based
LSP association are needed. As defined in [RFC4872] and being
considered in this document, "fully dynamic rerouting switches normal
traffic to an alternate LSP that is not even partially established
only after the working LSP failure occurs. The new alternate route
is selected at the LSP head-end node, it may reuse resources of the
failed LSP at intermediate nodes and may include additional
intermediate nodes and/or links." During the signaling procedure for
resource sharing based LSP setup/teardown, the behaviors of the nodes
along the path may be different from that in the MPLS networks as
well as the effect it may have on the traffic delivery.
As described in [RFC6689], ASSOCIATION object is used to identify the
LSPs for restoration using association type "Recovery" [RFC4872] and
for resource sharing using association type "Resource Sharing"
[RFC4873].
This document reviews the signaling procedure for resource sharing-
based LSP setup/teardown for GMPLS-based circuit networks. This
includes the node behavior description, besides clarifying some un-
discussed points for this process. Two typical examples mentioned in
this document are LSP restoration and LSP re-optimization, where it
is desirable to share resources. This document does not define any
RSVP-TE signaling extensions. If necessary, discussions may be
provided to identify potential extensions to the existing RSVP-TE
protocol. It is expected that the extensions, if there are any, will
be addressed in separate documents.
2. Problem Statement
GMPLS restoration schemes and resource sharing-based LSP
setup/teardown are described in this section.
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2.1. GMPLS Restoration
2.1.1. 1+R Restoration
One example of the recovery scheme considered in this document is 1+R
recovery. The 1+R recovery is exemplified in Figure 1. In this
example, working LSP on path A-B-C-Z is pre-established. Typically
after a failure detection and notification on the working LSP, a
second LSP on path A-H-I-J-Z is established as a restoration LSP.
Unlike protection LSP, restoration LSP is signaled per need basis.
A --- B --- C --- Z
\ /
H --- I --- J
Figure 1: An example of 1+R recovery scheme
During failure switchover with 1+R recovery scheme, in general,
working LSP resources are not released and working and restoration
LSPs coexist in the network. Nonetheless, working and restoration
LSPs can share network resources. Typically when failure is
recovered on the working LSP, restoration LSP is no longer required
and torn down (e.g., revertive mode).
2.1.2. 1+1+R Restoration
Another example of the recovery scheme considered in this document is
1+1+R. In 1+1+R, a restoration LSP is signaled for the working LSP
and/or the protecting LSP after the failure has been detected and
notified on the working LSP or the protecting LSP. The 1+1+R
recovery is exemplified in Figure 2.
D --- E --- F
/ \
A --- B --- C --- Z
\ /
H --- I --- J
Figure 2: An example of 1+1+R recovery scheme
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In this example, working LSP on path A-B-C-Z and protecting LSP on
path A-D-E-F-Z are pre-established. After a failure detection and
notification on a working LSP or protecting LSP, a third LSP on path
A-H-I-J-Z is established as a restoration LSP. The restoration LSP
in this case provides protection against a second order failure.
Restoration LSP is torn down when the failure on the working or
protecting LSP is repaired.
[RFC4872] Section 14 defines PROTECTION object for GMPLS recovery
signaling. As defined, the PROTECTION object is used to identify
primary and secondary LSPs using S bit and protecting and working
LSPs using P bit. Furthermore, [RFC4872] defines the usage of
ASSOCIATION object for associating GMPLS working and protecting LSPs.
[RFC6689] Section 2.2 reviews the procedure for providing LSP
associations for GMPLS end-to-end recovery and covers the schemes
where the failed working LSP and/or protecting LSP are torn down.
This document reviews how the LSP association is to be provided for
GMPLS end-to-end recovery when using restoration LSP where working
and protecting LSP resources are kept reserved in the network after
the failure.
2.2. Resource Sharing-based LSP Setup/Teardown
+-----+ +------+
| F +------+ G +-------+
+--+--+ +------+ |
| |
| |
+-----+ +-----+ +--+--+ +-----+ +--+--+
| A +----+ B +-----+ C +--X---+ D +-----+ E |
+-----+ +-----+ +-----+ +-----+ +-----+
Figure 3: A Simple OTN Network
Using the network shown in Figure 3 as an example, LSP1 (A-B-C-D-E)
is the working LSP and it allows for resource sharing when the LSP is
dynamically rerouted due to link failure. Upon detecting the failure
of a link along the LSP1, e.g. Link C-D, node A needs to decide to
which alternative path it will establish to reroute the traffic. In
this case, A-B-C-F-G-E is chosen as the alternative path and the
resource on the path segment A-B-C is re-used by this to-be-
established path. Since this is an OTN network, different from
packet-switching network, the label has a mapping into the data plane
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resource used and also the nodes along the path needs to send
triggering commands to data plane nodes for setting up cross-
connection accordingly during the RSVP-TE signaling process. So, the
following issues are left un-described in the existing standards for
resource sharing based LSP setup/teardown in GMPLS-controlled circuit
networks:
o The purpose of using SE can still be fulfilled?
As described in [RFC3209], the purpose of make before break (MBB) is
to "not disrupt traffic or adversely impact network operations while
TE tunnel rerouting is in progress". Due to the nature of the GMPLS-
controlled circuit networks, the first point may not be able to be
fulfilled under certain scenarios. Thus, the name "make before
break" may no longer holds true and worth discussion.
o Is the current defined MBB method sufficient in support of resource
shared-based LSP setup/teardown?
In [RFC3209], the MBB method assumes the old and new LSPs share the
same tunnel ID (i.e., sharing the same source and destination nodes).
[RFC4873] does not impose this constraint but limit the resource
sharing usage in LSP recoveries only. [RFC6780] generalizes the
resource sharing application, based on the ASSOCIATION object, to be
useful in MPLS networks as well as in non-LSP association such as
Voice Call Waiting. Recently, there are also requirements to
generalize resource sharing of LSP with different tunnel IDs, such as
the one mentioned in [PCEP-RSO] and LSPs with LSP-stitching across
multi-domains. Thus, how the signaling process can make intermediate
nodes be aware of this resource sharing constraint and behavior
accordingly is an issue that needs to be described and discussed.
o Other issues such as what is the reservation style assigned to the
original LSP, and what is the node behavior during the traffic
reversion, in the GMPLS-controlled circuit networks, are missing and
should be clarified.
3. RSVP-TE Signaling For Restoration LSP Association
Where GMPLS end-to-end recovery scheme needs to employ restoration
LSP while keeping resources for the working and/or protecting LSPs
reserved in the network after the failure, restoration LSP is
signaled with ASSOCIATION object that has association type set to
"Recovery" [RFC4872] with the association ID set to the LSP ID of the
LSP it is restoring. For example, when a restoration LSP is signaled
for a working LSP, the ASSOCIATION object in the restoration LSP
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contains the association ID set to the LSP ID of the working LSP.
Similarly, when a restoration LSP is signaled for a protecting LSP,
the ASSOCIATION object in the restoration LSP contains the
association ID set to the LSP ID of the protecting LSP.
The procedure for signaling the PROTECTION object is specified in
[RFC4872]. Specifically, restoration LSP being used as a working LSP
is signaled with P bit cleared and being used as a protecting LSP is
signaled with P bit set.
As discussed in Section 1 of this document, [RFC6689] Section 2.2
reviews the procedure for providing LSP associations for the GMPLS
end-to-end recovery scheme using restoration LSP where the failed
working LSP and/or protecting LSP are torn down.
4. RSVP-TE Signaling Procedure For Resource Sharing During LSP
Setup/Teardown
For LSP restoration upon failure, as explained in Section 11 of
[RFC4872], the purpose of using MBB is to re-use existing resource.
Thus, the behavior of the intermediate nodes during rerouting process
will not impact on traffic since it has been interrupted due to the
already broken working LSP.
However, for the following two cases, the behavior of intermediate
nodes may impact the traffic delivery: (1) LSP reversion; (2) LSP
optimization. Another dimension that needs separate attention is how
to correlate the two LSPs sharing resource. For the ones sharing
same tunnel ID, the majority description is provided in existing
standards [RFC3209] [RFC4872]. For the LSPs with different Tunnel
IDs, signaling procedure is clarified in this section.
4.1. LSPs with Identical Tunnel ID
For resource sharing among LSPs with identical tunnel IDs, SE flag
and ASSOCIATION object are used together. The former is to enable
sharing and the ASSOCIATION object with association type "Resource
Sharing" [RFC4873] is to identify the two associated LSPs.
As a first step, in order to allow resource sharing, the original LSP
setup should explicitly carry the SE flag in the SESSION_ATTRIBUTE
object during the initial LSP setup, irrespective of the purpose of
resource sharing.
The basic signaling procedure for alternative LSP setup has been
described by existing standards. In [RFC3209], it describes the
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basic MBB signaling flow for MPLS-TE networks. [RFC4872] adds
additional information when using MBB for LSP rerouting.
As mentioned before, for LSP setup/teardown in GMPLS-controlled
circuit networks, the network elements along the path need to send
cross-connection setup/teardown commands to data plane node(s) either
during the PATH message forwarding phase or the RESV message
forwarding phase.
4.1.1. LSP Setup
For LSP restoration, the complete signaling flow processes for both
LSP restorations upon failure and LSP reversion upon link failure
recovery are described.
Table 1: Node Behavior during LSP Restoration Setup
---------+---------------------------------------------------------
Category | Node Behavior during LSP Reversion
---------+---------------------------------------------------------
C1 + Reusing existing resource on both input and output
+ interfaces.
+ This type of nodes only needs to book the existing
+ resource when receiving the PATH message and no cross-
+ connection setup command is needed when receiving
+ the RESV message.
---------+---------------------------------------------------------
C2 + Reusing existing resource only on one of the interfaces,
+ either input or output interfaces and need to use new
+ resource on the other interface.
+ This type of nodes needs to book the resource on the
+ interface where new resource are needed and re-use the
+ existing resource on the other interface when it receives
+ the PATH message. Upon receiving the RESV message, it
+ needs to send the re-configuration the cross-connection
+ command to its corresponding data plane node.
---------+---------------------------------------------------------
C3 + Using new resource on both interfaces.
+ This type of nodes needs to book the new resource when
+ receiving PATH and send the cross-connection setup
+ command upon receiving RESV.
---------+---------------------------------------------------------
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For LSP rerouting upon working LSP failure, using the network shown
in Figure 3 as an example.
Working LSP: A-B-C-D-E
Restoration LSP: A-B-C-F-G-E
The restoration LSP may be calculated by the head end nodes or a Path
Computation Element (PCE) [RFC4655]. Assume that the cross-
connection configuration command is sent by the control plane nodes
during the RESV forwarding phrase, the node behavior for setting up
the alternative LSP can be categorized into the three categories
shown in Table 1.
+---+ +---+ +---+ +---+ +---+ +---+
| A | | B | | C | | F | | G | | E |
+-+-+ +-+-+ +-+-+ +-+-+ +-+-+ +-+-+
| | | | | |
| PATH | | | | |
C1 +----------X+ C1 | | | |
| | | | | |
| | PATH | | | |
| +----------X+ C2 | | |
| | | PATH | | |
| | +----------X+ C3 | |
| | | | PATH | |
| | | +----------X|C3 |
| | | | | PATH |
| | | | +------------X+ C3
| | | | | |
| | | | | RESV |
| | | | C3+X------------+ C3
| | | | RESV | |
| | | C3 +X----------+ |
| | | RESV | | |
| | C2+X----------+ | |
| | RESV | | | |
| C1 +X----------+ | | |
| RESV | | | | |
C1 +X----------+ | | | |
| |
Figure 4: Restoration LSP Setup Signaling Procedure
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As shown in Figure 4, depending on whether the resource is re-used or
not, the node behaviors differ. This deviates from normal LSP setup
since some nodes do not need to re-configure the cross-connection,
and thus should not be viewed as an error. Also, the judgment
whether the control plane node needs to send a cross-connection
setup/modification command to its corresponding data plane node(s)
relies on the check whether the following two cases holds true: (1)
the PATH message received include a SE reservation style; (2) the
PATH message identifies a LSP that sharing the same tunnel ID as the
LSP to share resource with. For the second point, the processing
rules and configuration of ASSOCATION object defined in [RFC4872] are
followed.
4.1.2. LSP Reversion
If the LSP rerouting is revertive, which is a common requirement in
transport networks [LSP-restoration], the traffic will be reverted to
the working LSP if its failure is recovered. The three types of
nodes classified above also have different behaviors during the
process for tearing down the alternative LSP, as explained in Table 2.
Table 2: Node Behavior during LSP Reversion
---------+---------------------------------------------------------
Category | Node Behavior during LSP Reversion
---------+---------------------------------------------------------
D1 + Resource reused on both interfaces.
+ When receiving PATH-TEAR, it only deletes the alternative
+ LSP state info in the control plane without changing the
+ cross-connection.
---------+----------------------------------------------------------
D2 + Resource reused on only one interface.
+ When receiving PATH-TEAR, it deletes the alternative path
+ state information in the control plane as well as release
+ the resource on the interface that is not re-used between
+ the working and Restoration LSP.
---------+----------------------------------------------------------
D3 + No resources are reused.
+ When receiving PATH-TEAR, it deletes the state information
+ related to the alternative LSP as well as tears down the
+ cross-connection to release the resource.
---------+----------------------------------------------------------
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It is worth noting there are both interruptions during the rerouting
and reverting procedure. Note that before the working LSP failure
recovers, the LSP in the control plane is still running and also it
views the data plane resource still belongs to the working LSP.
However, the re-used resource also belongs to the alternative LSP and
these resources are actually used by the alternative LSP. So when
the working LSP recovers, it needs to fresh the signaling messages to
re-establish the working LSP cross-connection. The process would be
similar to that shown in Figure 4, but running along the nodes on the
working LSP path (i.e., A-B-C-D-E). Note this will interrupt the
traffic delivery on the alternative LSP (i.e., Making the working LSP
While Breaking the alternative LSP). This point is different from
that of the MPLS networks. If no traffic interruption is mandated,
mechanisms to ensure that the traffic can still be delivered should
be employed and is outside the scope of this document.
Figure 5 shows the signaling process of the alternative LSP teardown
during the LSP reversion. Similar to that of the alternative LSP
setup process, the nodes may not need to reconfigure the cross-
connection and the rationale is similar to that described above. For
alarm-free LSP deletion in optical networks, the mechanisms described
in Section 6 of [RFC4208] should be followed.
+---+ +---+ +---+ +---+ +---+ +---+
| A | | B | | C | | F | | G | | E |
+-+-+ +-+-+ +-+-+ +-+-+ +-+-+ +-+-+
| | | | | |
| PATHTEAR | | | | |
D1 +----------X+ D1 | | | |
| | | | | |
| | PATHTEAR | | | |
| +----------X+ D2 | | |
| | | PATHTEAR | | |
| | +----------X+ D3 | |
| | | | PATHTEAR | |
| | | +----------X|D3 |
| | | | | PATHTEAR |
| | | | +------------X+ D3
| | | | | |
Figure 5: Tear-down of Alternative LSP for LSP Reversion
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4.1.3. LSP Re-optimization Setup and Reversion
For LSP re-optimization where the new LSP and old LSPs share resource,
the signaling flow for new LSP setup and old LSP teardown is similar
to that are shown in Figure 4 and 5.
The issue that should be noted is the traffic will be disrupted if
the new path setup process changes the cross-connection configuration
of the nodes along the old LSP. If no traffic interruption is
desirable, it should either ensure that the old and new LSP does not
share the resource other than the source and destination nodes or
using other mechanisms. This is out the scope of this document.
4.2. LSPs with Different Tunnel IDs
For two LSPs with different Tunnel IDs, the ASSOCIATION object is
used to both specify they are sharing resource (by setting
ASSOCIATION type as "Resource Sharing" (value 2) as well as identify
these correlated LSPs. There are two types: (1) sharing the common
nodes, such as segment recovery, the source and destination nodes of
the segment recovery LSP is the intermediate nodes along the working
LSPs; (2) resource sharing is used in a generalized context (such as
multi-layer or multi-domain networks); it may result in either
sharing source nodes in common, or destination nodes in common, or
non end points in common, if viewed from one domain's perspective.
The path computation can either be performed by the source node or
edge nodes for the path/path segment or carried out by the PCE, such
as the one explained in [PCEP-RSO]. This document does not impose
any constraint with regard to path computation.
In [RFC4873], it only considers resource sharing for LSP segment
recovery. The ASSOCIATION object configuration is limited. [RFC6780]
extends the usage of ASSOCIATION objects to cover generalized
resource sharing applications. The extended ASSOCIATION object is
primarily defined for MPLS-TP, but it can be applied in a wider scope
[RFC6780]. It can be used in the second types mentioned above. The
configuration and processing rules of extended ASSOCIATION object
defined in [RFC6780] should be obeyed. The only issue that need pay
attention to is that uniqueness of LSP association for the second
type should be guaranteed when crossing the layer or domain boundary.
The mechanisms for how to ensure this are outside of the scope of
this document.
Other than this, the signaling flow for this type of resource sharing
is similar to description provided in Section 4.1.1. Similar to what
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is discussed in previous sections, the traffic delivery may be
interrupted. Depending on whether the short traffic interruption is
acceptable or not, additional mechanisms may needed and are outside
of the scope of this document.
5. Security Considerations
This document reviews procedures defined in [RFC4872] and [RFC6689]
and does not define any new procedure. This document does not incur
any new security issues other than those already covered in [RFC3209]
[RFC4872] [RFC4873] and [RFC6780].
6. IANA Considerations
This informational document does not make any requests for IANA
action.
7. Acknowledgement
The authors would like to thank George Swallow for the discussions on
the GMPLS restoration.
8. References
8.1. Normative References
[RFC3209] D. Awduche et al, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC3209, December 2001.
[RFC3473] L. Berger, Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC
3473, January 2003.
[RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching
(GMPLS) Architecture", RFC 3945, October 2004.
[RFC4203] Kompella, K., and Rekhter, Y., "OSPF Extensions in
Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4203, October 2005.
[RFC4872] J.P. Lang et al, "RSVP-TE Extensions in Support of End-
to-End Generalized Multi-Protocol Label Switching (GMPLS)
Recovery", RFC4872, May 2007.
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[RFC4873] L. Berger et al, "GMPLS Segment Recovery", RFC4873, May
2007.
[RFC6689] L. Berger, "Usage of the RSVP ASSOCIATION Object", RFC
6689, July 2012.
[RFC6780] L. Berger et al, "RSVP ASSOCIATION Object Extensions",
RFC6780, October 2012.
8.2. Informative References
[PCEP-RSO] X. Zhang, et al, "Extensions to Path Computation Element
Protocol (PCEP) to Support Resource Sharing-based Path
Computation", work in progress, February 2014.
[RFC4426] Lang, J., Rajagopalan, B., and Papadimitriou, D.,
"Generalized Multiprotocol Label Switching (GMPLS)
Recovery Functional Specification", RFC 4426, March 2006.
[RFC4427] Mannie, E., and Papadimitriou, D., "Recovery (Protection
and Restoration) Terminology for Generalized Multi-
Protocol Label Switching, RFC 4427, March 2006.
[RFC4655] A. Farrel et al, "A Path Computation Element (PCE)-Based
Architecture", RFC4655, August 2006.
[RFC4208] Swallow, G., Drake, J., Ishimatsu, H., Rekhter, Y.,
"Generalized Multiprotocol Label Switching (GMPLS)
User-Network Interface (UNI): Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE)
Support for the Overlay Model", RFC4208, October 2005.
Zhang, et al. Expires March 2015 [Page 15]
draft-zhang-ccamp-gmpls-resource-sharing-proc September 2014
9. Authors' Addresses
Xian Zhang
Huawei Technologies
F3-1-B R&D Center, Huawei Base
Bantian, Longgang District
Shenzhen 518129 P.R.China
Email: zhang.xian@huawei.com
Haomian Zheng (editor)
Huawei Technologies
F3-1-B R&D Center, Huawei Base
Bantian, Longgang District
Shenzhen 518129 P.R.China
Email: zhenghaomian@huawei.com
Rakesh Gandhi (editor)
Cisco Systems, Inc.
Email: rgandhi@cisco.com
Zafar Ali
Cisco Systems, Inc.
Email: zali@cisco.com
Gabriele Maria Galimberti
Cisco Systems, Inc.
Email: ggalimbe@cisco.com
Pawel Brzozowski
ADVA Optical
Email PBrzozowski@advaoptical.com
Zhang, et al. Expires March 2015 [Page 16]
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