Network Working Group Y. Lee
Internet Draft Huawei
Intended status: Standard Track G. Bernstein
Expires: May 2008 Grotto Networking
October 29, 2007
Path Computation Element Communication Protocol (PCEP) Requirements
and Extensions for the Support of Wavelength Switched Optical
Networks
draft-lee-pce-wson-routing-wavelength-00.txt
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Abstract
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This memo provides application-specific PCEP requirements and
protocol enhancements for the support of Wavelength Switched Optical
Networks (WSON). Lightpath provisioning in WSONs requires a routing
and wavelength assignment (RWA) process. Different computational
architectures for the RWA process are given and the PCEP extensions
needed to support these architectures are defined.
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 RFC-2119 0.
Table of Contents
1. Terminology.................................................3
2. Introduction................................................4
3. Background: RWA Computation Architectures....................4
4. PCECP Requirements..........................................5
4.1. RWA Computation Options.................................6
4.2. Timeliness Characteristics of lightpath.................7
4.3. Duration of lightpath...................................7
4.4. Optimization Degree.....................................8
4.5. Wavelength Selection Preference.........................8
4.6. Wavelength Assignment and Wavelength Set Information.....9
4.7. Lightpath Route Parameters..............................9
5. Protocol extensions for support of WSON Routing and Wavelength
Assignment (RWA)...............................................9
5.1. RWA Computation Options.................................9
5.2. Lightpath Route Parameter TLV..........................11
5.3. Wavelength Selection Preferences.......................12
5.4. Wavelength Suggestion/Restriction TLV..................14
5.5. Error Indicator........................................14
5.6. NO-PATH Indicator......................................14
6. Manageability Considerations................................15
6.1. Control of Function and Policy.........................15
6.2. Information and Data Models, e.g. MIB module...........16
6.3. Liveness Detection and Monitoring......................16
6.4. Verifying Correct Operation............................16
6.5. Requirements on Other Protocols and Functional Components16
6.6. Impact on Network Operation............................16
7. Security Considerations.....................................17
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8. IANA Considerations........................................17
9. Acknowledgments............................................17
10. References................................................17
10.1. Normative References..................................17
10.2. Informative References................................18
Author's Addresses............................................18
Intellectual Property Statement................................19
Disclaimer of Validity........................................19
1. Terminology
The terminology explained herein complies with [RFC4655].
PCC: Path Computation Client: Any client application requesting a
path computation to be performed by a Path Computation Element.
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.
TED: Traffic Engineering Database which contains the topology and
resource information of the domain. The TED may be fed by IGP
extensions or potentially by other means.
PCECP: The PCE Communication Protocol: PCECP is the generic abstract
idea of a protocol that is used to communicate path computation
requests a PCC to a PCE, and to return computed paths from the PCE to
the PCC. The PCECP can also be used between cooperating PCEs.
PCEP: The PCE communication Protocol: PCEP is the actual protocol
that implements the PCECP idea.
RWA: Routing and Wavelength Assignment
WSON: Wavelength Switched Optical Networks: WDM based optical
networks in which switching is performed selectively based on the
center wavelength of an optical signal.
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 RFC 2119 [RFC2119].
These terms are also used in the parts of this document that specify
requirements for clarity of specification of those requirements.
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2. Introduction
[RFC4655] defines the PCE based Architecture and explains how a Path
Computation Element (PCE) may compute Label Switched Paths (LSP) in
Multiprotocol Label Switching Traffic Engineering (MPLS-TE) and
Generalized MPLS (GMPLS) networks at the request of PCCs. A PCC is
shown to be any network component that makes such a request and may
be for instance an Optical Switching Element with a WDM network. The
PCE, itself, can be located anywhere within the network, and may be
within an optical switching element, an NMS or Operational Support
System (OSS), or may be an independent network server.
The PCECP is the communication protocol used between PCC and PCE, and
may also be used between cooperating PCEs. [RFC4657] sets out the
common protocol requirements for the PCECP. Additional application-
specific requirements for PCECP are deferred to separate documents.
This document provides a set of application-specific PCECP
requirements and protocol enhancements for support of path
computation in Wavelength Switched Optical Network (WSON). WSON
refers to Wavelength Division Mulitiplexing (WDM) based optical
networks in which switching is performed selectively based on the
wavelength of an optical signal. The path in WSON is referred to as
a lightpath. In order to provision a light path, both routing and
wavelength assignment (RWA) are required.
3. Background: RWA Computation Architectures
The WSON framework [WSON Frame] document defines the following RWA
computation architectures.
o Combined RWA --- Both routing and wavelength assignment are
performed at a single computational entity. This choice assumes
that computational entity has sufficient WSON network link/nodal
and topology information to be able to compute RWA.
o Separate Routing and WA --- Separate entities perform routing and
wavelength assignment. The path obtained from the routing
computational entity must be furnished to the entity performing
wavelength assignment.
o Routing with Distributed WA --- Routing is performed at a
computational entity while wavelength assignment is performed in a
distributed fashion across the nodes along the path.
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For the Combined RWA architecture, there are two possible computing
entities: (i) the NE is the computational entity -- in this case,
there is no separate PCE as the NE assumes PCE function; (ii) a
separate PCE is the computational entity. This document is only
concerned with case (ii). In this case, the PCE should perform both
routing (R) and wavelength assignment (WA) upon request of the PCC.
For the Separate Routing and Wavelength architecture, there can be
two variations:
o A separate PCE will perform only wavelength assignment (WA) while
the NE performs the route calculation based on its local knowledge.
In this case, the NE should furnish the route list to the PCE so
that the PCE would be able to assign wavelength to the route.
o One PCE performs the routing (R) function while another PCE
performs the Wavelength Assignment (WA) function in a tandem
fashion. The fact that two PCEs are involved (one for Routing and
one for Wavelength Assignment (WA)) could be invisible to the
original PCC.
For the Routing with Distributed WA architecture, the PCE is only
responsible for routing (i.e., path computation), not for exact
wavelength assignment. The exact assignment of wavelength would be
performed at the NEs along the path in a distributed fashion. However,
the PCE may choose to limit the wavelengths that can be used (i.e.,
suggesting the wavelength set to the NEs)
4. PCECP Requirements
This section provides the PCECP requirements to support WSON routing
and wavelength assignment (RWA) application. The requirements
specified in this section are detailed requirements based on high-
level specification in the WSON Framework draft [WSON FRAME]. The
requirements specified here should be regarded as application-
specific requirements and are justifiable based on the extensibility
clause found in section 6.1.14 of [RFC4657]:
The PCECP MUST support the requirements specified in the application-
specific requirements documents. The PCECP MUST also allow
extensions as more PCE applications will be introduced in the future.
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The PCEP SHOULD support the following capabilities either via
creation of new objects and/or modification of existing object where
applicable.
4.1. RWA Computation Options
The following RWA computation options should be conveyed in the PC
Request:
o The request is for Wavelength Assignment (WA) only. This case may
arise when the NE is capable of route calculation at the node
level (e.g., via an IGP-TE) but with no wavelength information
available at the node level, or when two PCEs work in tandem with
one performing the routing (R) function and another wavelength
assignment (WA). In either case, the calculated route list at one
computing entity should be supplied in the request message to the
other computing entity where WA is applied.
o The request is for both Routing and Wavelength Assignment (R+WA).
This case may arise when the NE is not capable of both route
calculation and wavelength assignment at the node level or a more
optimal RWA is desired.
o The request is for Routing (R) only. This case may arise when the
NE is not capable of route calculation at the node level while
wavelength assignment is done at the node level in a distributed
fashion.
o The request is for Routing (R) with the suggested/restricted
wavelength set. This is a variation from the Routing only option.
With this option, the PCE computes the route and the candidate
wavelengths associated with the route. In this case, the exact
wavelength assignment is to be performed at the NE level.
The corresponding PC Reply message should include the following
information:
o An indicator that conveys the original request was for (i) WA only;
(ii) R+WA; (iii) R only; (iv) R with the suggested/restricted
wavelength set
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o The route list and the recommended wavelength(s) to be used for
the route. The encoding of this requirement can be fulfilled with
the ERO object and ERO Label subobject within the ERO as defined
in [RFC3471]. See section 4.6 for details of wavelength label
assignment.
o In the case of failure to find a proper route or wavelength
assigned to the route, proper reasons for the failure should be
conveyed: (i) route not found; (ii) wavelength not found (i.e.,
wavelength blocking); (iii) both route and wavelength not found.
4.2. Timeliness Characteristics of lightpath
The request may indicate specific timeliness lightpath
characteristics associated with the request:
o Time Critical: this type of request is useful for those lightpath
establishment requests used for restoration of service or other
high priority real time services.
o Soft Time Bounds: this type of request is a more typical new
connection request. While expected to be responsive, there should
be more time to take into account network optimization.
o Scheduled: this type of request is useful when the requested
lightpath connections are not time critical (i.e., the request is
significantly ahead of their intended "in-service" time. It is to
be noted that we will not explicitly deal with scheduled case in
this document but the optimization can be handled via [PCE-GCO].
The reply should indicate the original timeliness characteristics of
the lightpath request with path computation results.
4.3. Duration of lightpath
The request may indicate specific lightpath duration information
associated with the request. This may be useful to the PCE since it
is not worthwhile to optimize lightpaths with relatively short
duration as compared to pseudo-static paths.
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4.4. Optimization Degree
The PC Request Message should indicate the degree of optimization
associated with lightpath computation.
o Concurrent Optimization: multiple lightpaths requested at one time.
o Lightpath(s) and backup lightpath(s) requested at one time.
o Sequential Optimization: single lightpath requested at a time.
The PC Reply Message should include the original optimization degree
associated with the request when replying the path computation
results.
4.5. Wavelength Selection Preference
The PC Request may indicate the Wavelength Selection Preference to
which a path computation request is applied.
The Wavelength Selection Preference to be supported at the minimum is:
o Random
o First Fit
o Most Used
o Least Loaded
o Don't care: default
Note that the objective functions to be supported for a single LSP
request are listed in [PCEP] and [PCE-OF] and that the objective
functions to be supported for a concurrent LSP request are listed in
[PCE-GCO] and [PCE-OF].
The PC Reply should indicate which wavelength selection preference
has actually been applied.
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4.6. Wavelength Assignment and Wavelength Set Information
The PCE MUST specify the wavelength assignment and/or wavelength set
information in response to the wavelength assignment/wavelength set
Request made by the PCC in the PCReq message.
If the original request is either for both Routing and Wavelength
Assignment or for Wavelength Assignment only, the exact wavelength
assignment result can be conveyed to PCC using the ERO object and ERO
Label subobject within the ERO. Note that this is not a new
requirement. Current PCEP allows this mechanism which is defined as
the Label Set mechanism in [RFC3471].
If the original request is for Routing with wavelength
suggested/restricted wavelength set, then the Wavelength Set
information must be provided to the PCC.
4.7. Lightpath Route Parameters
The following Lightpath Route Parameters should be indicated:
o Bidirectional Assignment of wavelengths for a bidirectional LSP
request.
o Possible simultaneous assignment of the same wavelength to primary
and backup paths.
The PC Reply Message should include the original lightpath route
parameter associated with the request when replying the path
computation results.
5. Protocol extensions for support of WSON Routing and Wavelength
Assignment (RWA)
5.1. RWA Computation Options
The PCE has to include the RWA computation option in the PCReq
message in order to convey a particular computation option. To
support such indication a new flag, the RC flag, is defined in the RP
(Request Parameter) Object. The PCE also has to include the
Directionality of Wavelength Assignment indicator when the request is
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for a bidirectional TE LSP. To support such indication a new flag, I
flag, is defined in the RP Object.
The RC flag and I flag are defined in the RP (Request Parameter)
object 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Flags |I|RC|D|M|F|O|B|R| Pri |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Request-ID-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// Optional TLV(s) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 RP object body format in the PCReq Message
RC bits (Routing wavelength Computation bits - 2 bits):
o 11: Request is for both R (Routing) and Wavelength Assignment (WA).
o 01: Request is for Wavelength Assignment (WA) only.
o 10: Request is for Routing (R) with suggested/restricted
Wavelength Set
o 00: Request is for Routing (R) only.
When RC bit is set to 11 in a PCReq message, the requesting PCC
requires the PCE to provide in the PCRep message the assigned
wavelength associated with the computed path. This request is for
both Routing (R) and Wavelength Assignment (WA).
When RC bit is set to 01 in a PCReq message, the requesting PCC
requires the PCE only to provide wavelength assignment (WA). In such
case, the PCC must provide the already computed route (as indicated
by the ERO and the Bandwidth Object following the RP object) to which
the PCE would assign the wavelengths. Note that this option is to
fulfill one of the RWA computational architectures, namely, the
Separate Routing and WA option.
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When RC bit is set to 10, then the PCE is expected to provide some
suggestive or restrictive wavelength information associated with the
route.
When RC bit is set to either 11, 01 or 10, then additional parameters
associated with the requested lightpath should be provided in
optional lightpath Route Parameter TLV (as specified in Section 4.7)
within the RP object. See Section 5.2 for the encoding of Lightpath
Route Parameter TLV.
When B bit is set in the RP object in a PCReq message, this indicates
that the path computation request relates to a bidirectional TE LSP
[PCEP]. In such case, a new flag, I flag, should be defined in the
RP object should be defined in order to indicate that a bidirectional
assignment of wavelength be required for the bidirectional TE LSP.
I bit (dIrectionality bit - 1 bit): When set, the request is a
bidirectional wavelength assignment. Otherwise, the request is a
unidirectional wavelength assignment.
The RP object in the PC Reply message should properly indicate the
original request for the RWA Computation (RC) bit and I bit that have
actually been applied by the PCE. The actual route list and
wavelength assignment is to be found in the ERO object and within an
ERO an ERO Label subobject. An ERO Label subobject can be used to
indicate the wavelength to be used at a particular node. Note that
current GMPLS signaling supports an explicit route object (ERO) and
within an ERO an ERO Label subobject.
5.2. Lightpath Route Parameter TLV
When the RC bit is set to either 11, 01 or 10 in the RP object
associated with PC Req message, then the following TLV should be
included as part of the RP object within the PC Request message.
The format of the Lightpath Route Parameter TLV is as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bidirectional Assignment of wavelengths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Same wavelength to primary and backup paths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type To be defined by IANA (suggested value = )
Length Variable
Value Bidirectional Assignment of wavelengths (0 or 1)
Same Wavelength to primary and backup (0 or 1)
Figure 2 The Lightpath Route Parameter TLV in the RP object in the
PC Rep Message
5.3. Wavelength Selection Preferences
When the RC (RWA Computation) option is associated with computing
wavelength assignment in the RP object of the PC Request message,
then the following Wavelength Selection Preference TLV may be
included in the RP object as an optional TLV.
The format of the Wavelength Selection Preference TLV is as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Wavelength Selection Preference |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TDB |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type To be defined by IANA (suggested value = )
Length Variable
Value Wavelength Selection Preference
Figure 3 The Wavelength Selection/Assignment Preferences TLV in
the RP object in the PC Rep Message
Five wavelength selection preferences are defined in this document
and their identifier should be assigned by IANA (suggested value)
Function
Code Description
1 Random
2 First Fit
3 Most Used
4 Least Loaded
5 Don't Care
The Wavelength Selection Preference TLV should also be included in
the RP object in the PC Reply message to indicate which wavelength
selection preference has actually been applied by the PCE in its
wavelength assignment procedure.
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5.4. Wavelength Suggestion/Restriction TLV
With the Routing with Distributed Wavelength Assignment option, the
PC Reply should specify the wavelength set information in response to
the wavelength assignment/wavelength set Request made by the PCC in
the PCReq message if so requested by the setting of the RC bit in the
RP object in the PCReq message.
We refer to this information as wavelength restriction TLV.
The encoding of wavelength Suggestion/Restriction TLV is to be
provided in the next version.
5.5. Error Indicator
To indicate errors associated with the RWA request, a new Error-Type
(15) and subsequent error-values are defined as follows for inclusion
in the PCEP-ERROR object:
A new Error-Type (15) and subsequent error-values are defined as
follows:
Error-Type=15 and Error-Value=1: if a PCE receives a RWA computation
request and the PCE is not capable of RWA, the PCE MUST send a PCErr
message with a PCEP ERROR object (Error-Type=15) and an Error-Value
(Error-Value=1). The corresponding RWA computation request MUST be
cancelled.
To indicate an error associated with policy violation, a new error
value "RWA not allowed" should be added to an existing error code for
policy violation (Error-Type=6) as defined in [PCEP].
Error-Type=6; Error-Value=3: if a PCE receives a RWA computation
request which is not compliant with administrative privileges (i.e.,
the PCE policy does not support RWA), the PCE sends a PCErr message
with a PCEP-ERROR Object (Error-Type=6) and an Error-Value (Error-
Value=3). The corresponding RWA computation MUST be cancelled.
5.6. NO-PATH Indicator
To communicate the reason(s) for not being able to find RWA
computation, the NO-PATH object can be used in the PCRep message.
The format of the NO-PATH object body is as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|C| Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// Optional TLV(s) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4 NO-PATH object format
Flags (16 bits). The C flag is defined in [PCEP].
Two new bit flags are defined in the NO-PATH-VECTOR TLV carried in
the NO-PATH Object:
0x08: when set, the PCE indicates that no path was found.
0x10: when set, the PCE indicates that no wavelength was found
associated with RWA computation in the PCRep message.
6. Manageability Considerations
Manageability of WSON Routing and Wavelength Assignment (RWA) with
PCE must address the following considerations:
6.1. Control of Function and Policy
In addition to the parameters already listed in section 8.1 of [PCEP],
a PCEP implementation SHOULD allow configuring the following PCEP
session parameters on a PCC:
o The ability to send a WSON RWA request.
In addition to the parameters already listed in section 8.1 of [PCEP],
a PCEP implementation SHOULD allow configuring the following PCEP
session parameters on a PCE:
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o The support for WSON RWA.
o The maximum number of synchronized path requests associated with
WSON RWA per request message.
o A set of WSON RWA specific policies (authorized sender, request
rate limiter, etc).
These parameters may be configured as default parameters for any PCEP
session the PCEP speaker participates in, or may apply to a specific
session with a given PCEP peer or a specific group of sessions with a
specific group of PCEP peers.
6.2. Information and Data Models, e.g. MIB module
Extensions to the PCEP MIB module defined in [PCEP-MIB] should be
defined, so as to cover the WSON RWA information introduced in this
document.
6.3. Liveness Detection and Monitoring
Mechanisms defined in this draft does not imply any new liveness
detection and monitoring requirements in addition to those already
listed in section 8.3 of [PCEP].
6.4. Verifying Correct Operation
Mechanisms defined in this draft does not imply any new verification
requirements in addition to those already listed in section 8.4 of
[PCEP]
6.5. Requirements on Other Protocols and Functional Components
The PCE Discovery mechanisms ([ISIS PCED] and [OSPF PCED]) may be
used to advertise WSON RWA path computation capabilities to PCCs.
6.6. Impact on Network Operation
Mechanisms defined in this draft does not imply any new network
operation requirements in addition to those already listed in section
8.6 of [PCEP].
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7. Security Considerations
This document has no requirement for a change to the security models
within PCEP [PCEP]. However the additional information distributed in
order to address the RWA problem represents a disclosure of network
capabilities that an operator may wish to keep private. Consideration
should be given to securing this information.
8. IANA Considerations
A future revision of this document will present requests to IANA for
codepoint allocation.
9. Acknowledgments
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2234] Crocker, D. and Overell, P.(Editors), "Augmented BNF for
Syntax Specifications: ABNF", RFC 2234, Internet Mail
Consortium and Demon Internet Ltd., November 1997.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE)
Communication Protocol Generic Requirements", RFC 4657,
September 2006.
[PCEP] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) communication Protocol (PCEP) - Version 1",
draft-ietf-pce-pcep, work in progress.
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[PCE-OF] Le Roux, JL., Vasseur, JP., and Y. Lee, "Objective Function
encoding in Path Computation Element communication and
discovery protocols", draft-ietf-pce-pce-of, work in
progress.
[PCE-GCO] Y. Lee, J.L. Le Roux, D. King, and E. Oki, "Path
Computation Element Communication Protocol (PCECP)
Requirements and Protocol Extensions In Support of Global
Concurrent Optimization", draft-ietf-pce-global-concurrent-
optimization, work in progress.
10.2. Informative References
[WSON-FRAME] Bernstein, G. and Lee, Y. (Editors), and W. Imajuku,
"Framework for GMPLS and PCE Control of Wavelength Switched
Optical Networks", draft-bernstein-ccamp-wavelength-
switched, work in progress.
[ISIS-PCED] Le Roux, J. and JP. Vasseur, "IS-IS protocol extensions
for Path Computation Element (PCE) Discovery", draft-ietf-
pce-disco-proto-isis, work in progress.
[OSPF-PCED] Le Roux, J. and JP. Vasseur, "OSPF protocol extensions
for Path Computation Element (PCE) Discovery", draft-ietf-
pce-disco-proto-ospf, work in progress.
Author's Addresses
Young Lee (ed.)
Huawei Technologies
1700 Alma Drive, Suite 100
Plano, TX 75075, USA
Phone: (972) 509-5599 (x2240)
Email: ylee@huawei.com
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Internet-Draft PCEP Extension for WSON November 2007
Greg Bernstein (ed.)
Grotto Networking
Fremont, CA, USA
Phone: (510) 573-2237
Email: gregb@grotto-networking.com
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Internet-Draft PCEP Extension for WSON November 2007
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