Networking Working Group JP. Vasseur
Internet-Draft Cisco Systems, Inc
Intended status: Standards Track October 18, 2006
Expires: April 21, 2007
A set of monitoring tools for Path Computation Element based
Architecture
draft-vasseur-pce-monitoring-01.txt
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Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
A Path Computation Element (PCE) based architecture has been
specified for the computation of Traffic Engineering (TE) Label
Switched Paths (LSPs) in Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) networks in the context of single or
multiple domains (where a domain is referred to as a collection of
network elements within a common sphere of address management or path
computational responsibility such as IGP areas and Autonomous
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Systems). In such PCE-based environment it is thus critical to
monitor the state of the path computation chain and potentially
gather various performance metrics with regards to the set of
involved PCE(s) that can be used for performance monitoring and
troubleshooting purposes. This document specifies procedures and
extensions to the Path Computation Element Protocol (PCEP) in order
to gather such information.
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 RFC 2119 [RFC2119].
Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Path Computation Monitoring messages . . . . . . . . . . . . . 4
3.1. Path Computation Monitoring Request message (PCMonReq) . . 4
3.2. Path Monitoring Reply message (PCMonRep) . . . . . . . . . 6
4. Path Computation Monitoring Objects . . . . . . . . . . . . . 6
4.1. MONITORING Object . . . . . . . . . . . . . . . . . . . . 7
4.2. PCE-ID Object . . . . . . . . . . . . . . . . . . . . . . 8
4.3. PROC-TIME Object . . . . . . . . . . . . . . . . . . . . . 9
4.4. TIMESTAMP Object . . . . . . . . . . . . . . . . . . . . . 11
5. Multi-destination monitoring . . . . . . . . . . . . . . . . . 11
6. Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7. Elements of procedure . . . . . . . . . . . . . . . . . . . . 12
8. Manageability Considerations . . . . . . . . . . . . . . . . . 13
9. To be considered in a further revision of this document . . . 13
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
11. Security Considerations . . . . . . . . . . . . . . . . . . . 14
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
13.1. Normative References . . . . . . . . . . . . . . . . . . . 14
13.2. Informative References . . . . . . . . . . . . . . . . . . 14
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 15
Intellectual Property and Copyright Statements . . . . . . . . . . 16
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1. Terminology
LSR: Label Switching Router.
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.
TE LSP: Traffic Engineering Label Switched Path.
TED: Traffic Engineering Database.
2. Introduction
The Path Computation Element (PCE) based architecture has been
specified in [RFC4655] for the computation of Traffic Engineering
(TE) Label Switched Paths (LSPs) in Multiprotocol Label Switching
(MPLS) and Generalized MPLS (GMPLS) networks in the context of single
or multiple domains where a domain is referred to as a collection of
network elements within a common sphere of address management or path
computational responsibility such as IGP areas and Autonomous
Systems.
In such PCE-based environment it is thus critical to monitor the
state of the path computation chain and potentially gather various
performance metrics with regards to the set of involved PCE(s) that
can used for performance monitoring and troubleshooting purposes.
This document specifies procedures and extensions to the Path
Computation Element Protocol (PCEP) ([I-D.ietf-pce-pcep]) in order to
monitor the path computation chain and gather various performance
metrics.
As discussed in [RFC4655], a TE LSP may be computed by one PCE
(referred to as single PCE path computation) or several PCE (referred
to as multiple PCE path computation). In the former case, the PCC
may be able to use IGP extensions to check the availability of the
PCE (see [I-D.ietf-pce-disco-proto-ospf] and
[I-D.ietf-pce-disco-proto-isis]) or PCEP using Keepalive messages.
In contrast, when multiple PCEs are involved in the path computation
chain an example of which being the use of the BRPC procedure defined
in [I-D.ietf-pce-brpc], the PCC's visibility is limited to the first
involved PCE. Thus, it is critical to define mechanisms in order to
gather performance metrics along the path computation chain (e.g.
liveness, path computation time at each PCE, propagation delays
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experienced by the path computation request betwen each PCE involved
in the path computation chain and so on).
3. Path Computation Monitoring messages
As defined in [I-D.ietf-pce-pcep], a PCEP message consists of a
common header followed by a variable length body made of a set of
objects that can either be mandatory or optional. As a reminder, an
object is said to be mandatory in a PCEP message when the object must
be included for the message to be considered as valid. The P flag
(defined in [I-D.ietf-pce-pcep]) is located in the common header of
each PCEP object and can be set by a PCEP peer to enforce a PCE to
take into account the related information during the path
computation. Because the P flag exclusively relates to a path
computation request, it MUST be cleared in the two PCEP messages
(PCEMonReq and PCMonRep message) defined in this document.
For each PCEP message type a set of rules is defined that specify the
set of objects that the message can carry. We use the Backus-Naur
Form (BNF) to specify such rules. Square brackets refer to optional
sub-sequences. An implementation MUST form the PCEP messages using
the object ordering specified in this document.
In this document we define two new PCEP messages referred to as the
Path Computation Monitoring request (PCMonReq) and Path Computation
Monitoring Reply (PCMonRep) message. The aim of the PCMonReq message
sent by a PCC to a PCE is to gather performance metrics on a set of
PCEs involved in a path computation chain. The PCMonRep message sent
by a PCE to a PCC is used to provide such data.
3.1. Path Computation Monitoring Request message (PCMonReq)
The Message-Type field of the PCEP common header for the PCMonReq
message is set to 8 (To be confirmed by IANA).
There is one mandatory object that MUST be included within a PCMonReq
message: the Monitoring object (see section Section 4.1). If the
Monitoring object is missing, the receiving PCE MUST send an error
message to the sender. Other objects are optional.
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The format of a PCMonReq message is as follows:
<PCMonReq Message>::= <Common Header>
<MONITORING>
[<lsp-request>]
[<pce-list>]
where:
<lsp-request>::= <RP>
<END-POINTS>
[<LSPA>]
[<BANDWIDTH>]
[<METRIC>]
[<RRO>]
[<IRO>]
[<LOAD-BALANCING>]
<pce-list>::=<pce>[<pce-list>]
<pce>::= [<PCE-ID>]
The SVEC, RP, END-POINTS, LSPA, BANDWIDTH, METRIC, ERO, IRO and LOAD-
BALANCING objects are defined in [I-D.ietf-pce-pcep].
A PCMonReq message is sent to gather various performance metrics
along a path computation chain. Such metrics may relate to a
specific path computation chain encoded in the form of a series of
PCE-ID objects defined in Section 4.2. Alternatively, it may be
desired to collect such performance metrics along the path
computation chain involved to compute a TE LSP. In that case, the TE
LSP attributes are characterized by the set of objects present in a
PCEP Path Computation request (PCReq) message (see
[I-D.ietf-pce-pcep]). Several metrics may be requested that are
specified by a set of objects defined in section Section 4. Note
that this set of objects is by all means not limitative and may be
extended in further revision of this document. The most simplest
form of metric is PCE liveness.
For the sake of illustraion, consider the two following examples:
Example 1: PCC1 requests to check the path computation chain should a
path computation be requested for a specific TE LSP named T1. A
PCMonReq message is sent that contains a MONITORING object specifying
a path computation check, along with the appropriate set of objects
(e.g. RP, END-POINTS, ...) that would be included in a PCReq message
for T1.
Example 2: PCC1 request to gather the processing time along the path
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computation chain selected for the computation of T1. In addition to
the objects listed in example 1, the PCMonReq message also contains
the PROC-TIME object defined in section Section 4.1.
Example 3: PCC2 request to gather performance metrics along the
specific path computation chain <pce1, pce2, pce3, pce7>. A PCMonreq
message is sent to PCE1 that contains a set of PCE-ID objects that
identify PCE1, PCE2, PCE3 and PCE7 respectively.
3.2. Path Monitoring Reply message (PCMonRep)
The Message-Type field of the PCEP common header for the PCMonRep
message is set to 9 (To be confirmed by IANA).
There is one mandatory objects that MUST be included within a
PCMonRep message: the Monitoring object (see sectionSection 4.1). If
the Monitoring object is missing, the receiving PCE MUST send an
error message to the requesting PCC. Other objects are optional.
The format of a PCReq message is as follows:
<PCMonRep Message>::= <Common Header>
<MONITORING>
[<RP>]
[<metric-pce-list>]
where:
<metric-pce-list>::=<metric-pce>[<metric-pce-list>]
<metric-pce>::=[<PCE-ID>]
[<PROC-TIME>]
[<TIME-STAMP>]
The SVEC, RP, END-POINTS, LSPA, BANDWIDTH, METRIC, ERO, IRO and LOAD-
BALANCING objects are defined in [I-D.ietf-pce-pcep].
4. Path Computation Monitoring Objects
Each new PCEP object defined in the document is compliant to the PCEP
object format defined in [I-D.ietf-pce-pcep], with the P flag and the
I flag cleared since these flags are exclusively related to path
computation request.
Several objects are defined in this section that may be also be
carried within the PCEP PCReq or PCRep messages defined in
[I-D.ietf-pce-pcep] when TE LSP path computation must be peformed in
addition to gathering peformance metrics. For example, when a PCC
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only requires performance metric gathering, the objects defined in
this section will be carried within PCMonReq and PCMonRep messages.
Conversely, if the PCC requires the computation of the TE LSP in
addition to gathering performance metrics, these objects will be
carried within PCReq and PCRep messages.
4.1. MONITORING Object
The MONITORING object MUST be carried within each PCMonReq and
PCMonRep messages and MAY be carried within PCERep and PCReq messages
(defined in [I-D.ietf-pce-pcep]) TE LSP path computation must be
peformed in addition to gathering peformance metrics. The MONITORING
object is used to specify the set of requested performance metrics.
The MONITORING Object-Class is to be assigned by IANA (recommended
value=16)
The MONITORING Object-Type is to be assigned by IANA (recommended
value=1)
The format of the MONITORING object body is 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|P|G|R|C|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| monitoring-id-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// Optional TLV(s) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Flags: 18 bits - The following flags are currently defined:
C (Check) - 1 bit: when set, this indicates that the performance
metric of interest is the PCE's availability.
R (Record) - 1 bit: when set, this indicates that the PCE's
indentifier MUST be included in the corresponding PCMonRep message in
the form of a PCE-ID object.
G (General) - 1 bit: when set, this indicates that the set of
requested performance metric is not related to a particular TE LSP
computation: this is a general performance metric, such as the
average processing time computed over the X last minutes, ... When
the requested performance metric is related to a particular TE LSP
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computation, the G bit MUST be cleared.
P (Processing Time) - 1 bit: the P bit of the MONITORING object
carried in a PCMonReq message is set to indicate that the processing
times is a metric of interest, in which case a PROC-TIME object MUST
be inserted in the corresponding PCMonRep message. The P bit MUST
always be set in a PCMonRep message if also set in the corresponding
PCMonReq message.
I (Incomplete) - 1 bit: the I bit MUST be set by a PCE that supports
the PCMonReq message, which does not trigger any policy violation but
that cannot provide the set of requested performance metrics for
unspecified reasons.
Monitoring-id-number (32 bits). The monitoring-id-number value
combined with the source IP address of the PCC and the PCE address
uniquely identify the monitoring request context. The monitoring-id-
number MUST be incremented each time a new monitoring is sent to a
PCE. The value 0x0000000 is considered as invalid. If no reply to a
monitoring request is received from the PCE, and the PCC wishes to
resend its path computation monitoring request, the same monitoring-
id-number MUST be used. Conversely, different monitoring-id-number
MUST be used for different requests sent to a PCE. The same
monitoring-id-number may be used for path computation monitoring
requests sent to different PCEs. The path computation monitoring
reply is unambiguously identified by the IP source address of the
replying PCE.
No optional TLVs are currently defined.
4.2. PCE-ID Object
The PCE-ID Object is used in a PCMonReq or a message to record the IP
address of the PCE for which performance metrics are collected and in
a PCMonRep or a PCRep message to record the IP address of the PCE
reporting performance metrics or that was involved in the path
computation chain.
The PCE-ID Object-Class is to be assigned by IANA (recommended
value=17)
The PCE-ID Object-Type is to be assigned by IANA (recommended
value=1)
The format of the PCE-ID Object 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| address-type | Lenght |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// PCE IP Address //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Address-type: 1 IPv4 2 IPv6
Length 4 (IPv4) or 16 (IPv6)
PCE IP Address: The PCE IP address. It is RECOMMENDED to use the
same IP address as the address used in the PCE-ADDRESS sub-TLV
defined in [I-D.ietf-pce-disco-proto-ospf] and
[I-D.ietf-pce-disco-proto-isis]should a dynamic discovery mechanism
be used for PCE discovery.
4.3. PROC-TIME Object
The PROC-TIME object MUST be present within a PCMonRep or a PCRep
message if the P bit of the MONITORING object carried within the
corresponding PCMonReq or PCReq message is set. The PROC-TIME object
is used to report various processing time related metrics.
A PCC may request processing time metrics that are not related to a
particular request, in which case the request is qualified as a
"general" request. For example, the PCC may want to know the
minimum, maximum and average processing times on a particular PCE (in
this case, general requests can only be made by using PCMonReq/
PCMonRep messages).
The Current-processing-time field is used to report the processing
time for a particular request the characteristics of which are
specified in the corresponding PCMonReq or PCReq message.
The algorithm(s) used by a PCE to compute such metrics are out of the
scope of this document but a flag is specified that is used to
indicate to the requester whether the processing time values were
estimated or computed. For example, if the processing time for a
specific TE LSP computation is requested, the PCE may either (1)
estimate the processing time without performing an actual path
computation or (2) effectively perform the computation to report the
processing time.
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When the processing time is requested in addition to a path
computation, the PROC-TIME object always report the actual processing
time for that request and thus the E bits MUST be cleared.
Furthermore, the same object can be used to report the processing
time for a particular request in addition to the general processing
times computed for a set of requests over a period of time.
The PROC-TIME Object-Class is to be assigned by IANA (recommended
value=18)
The PROC-TIME Object-Type is to be assigned by IANA (recommended
value=1)
The format of the PROC-TIME object body is 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Current-processing-time |E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min-processing-time |E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max-processing-time |E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Average-processing time |E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Variance-processing-time |E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Flags: 18 bits - No Flags are currently defined:
E (Estimated) - 1 bit: when set, this indicates that the reported
metric value is based on estimated processing time as opposed to
actual computation(s).
Current-processing-time: This field indicates in milliseconds the
processing time for the path computation of interest characterized in
the corresponding PCMonReq message and MUST be set to 0x00000000 if
the request is a general request (does not relate to a particular
path computation request). If the G flag of the MONITORING object is
set then this field MUST be set to 0x00000000.
Min-processing-time: This field indicates in milliseconds the minimum
processing time. The equation/algorithm used to compute this value
is implementation specific and outside of the scope of this document
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(A PCE may decide to compute the minimum processing time over a
period of times, for the last N path computation requests, ...). If
the G flag of the MONITORING object is cleared then this field MUST
be set to 0x00000000.
Max-processing-time: This field indicates in milliseconds the maximum
processing time. The equation/algorithm used to compute this value
is implementation specific and outside of the scope of this document
(A PCE may decide to compute the maximum processing time over a
period of times, for the last N path computation requests, ...). If
the G flag of the MONITORING object if cleared then this field MUST
be set to 0x00000000.
Average-processing-time: This field indicates in milliseconds the
average processing time. The equation/algorithm used to compute this
value is implementation specific and outside of the scope of this
document (A PCE may decide to compute the average processing time
over a period of times, for the last N path computation requests,
...). If the G flag of the MONITORING object if cleared then this
field MUST be set to 0x00000000.
Variance-processing-time: This field indicates in milliseconds the
variance of the processing times. The equation/algorithm used to
compute this value is implementation specific and outside of the
scope of this document (A PCE may decide to compute the variance
processing time over a period of times, for the last N path
computation requests, ...). If the G flag of the MONITORING object
if cleared then this field MUST be set to 0x00000000.
More granularity may be introduced in further revision of this
document to get a monitoring metric for a general request of a
particular class (e.g. all PCReq of priority X).
4.4. TIMESTAMP Object
A TIMESTAMP object will be specified in a further revision of this
document that could be used to provide indication on the time at
which a PCMonReq message has been received by a PCE and the time at
which the PCMonReq message has been relayed to the next-hop PCE or
the time at which a PCMonRep message has been sent to the requester.
5. Multi-destination monitoring
In a further revision of this document, a new object will be
specified allowing a PCC or a user to gather performance metrics for
a set of destinations using a single PCMonReq message. For example,
using a single PCMonreq message originated by the PCC, performance
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metrics for the set of path computation chains involved in the
computation of a set of TE LSPs will be gathered. Such set of
destinations could be specified in the form of a subnets.
6. Policy
The receipt of a PCMonReq message may trigger a policy violation on
some PCE in which case the PCE MUST send a PCErr message with Error-
Type=4 and Error-value=3.
7. Elements of procedure
I bit processing: as indicated in section Section 4.1, the I bit MUST
be set by a PCE that supports the PCMonReq message, which does not
trigger any policy violation but that cannot provide the set of
required performance metrics for unspecified reasons. Once set, the
I bit MUST NOT be changed by a receiving PCE.
Reception of a PCMonReq message: upon receiving a PCMonReq message,
if the PCE does not support the PCMonReq message, the PCE MUST send a
PCErr message with Error-type=11 and Error-value=1
If the PCE supports the PCMonReq message but the request is
prohibited by policy, the PCE MUST send a PCErr message with Error-
Type=12 and Error-value=1.
If the PCE supports the PCMonReq and the request is not prohibited by
policy, the receiving PCE MUST first determine whether it is the last
PCE of the path computation chain the process of which is being
outside of this document. If the PCE is not the last element of the
path computation chain, the PCMonReq message is relayed to the next
hop PCE: such next-hop may either be specified by means of a PCE-ID
object present in the PCMonReq message or dynamically determined by
means of a procedure outside of the scope of this document.
Conversely, if the PCE is the last PCE of the path computation chain,
the PCE originates a PCMonRep message that contains the requested
objects according to the set of requested performance metrics listed
in the MONITORING object carried in the corresponding PCMonReq
message.
Reception of a PCMonRep message: upon receiving a PCMonRep message,
the PCE processes the request, adds the relevant objects to the
PCMonRep message and forwards the PCMonRep message to the upstream
requesting PCE or PCC.
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Special case of Multi-destination monitoring: performance monitoring
request related to more than one destinations may lead to involve a
set of path computation chains. In that case, a PCE sends each copy
of the PCMonReq message to each downstream PCE of each path
computation chain.
8. Manageability Considerations
To be addressed in a further revision of this document.
9. To be considered in a further revision of this document
IT might be desirable to modify the format of the PCMonReq and
PCMonRep messages to support the bundling of multiple performance
metrics collection for a set of TE LSPs.
10. IANA Considerations
Two new PCEP (specified in [I-D.ietf-pce-pcep]) messages are defined
in this document:
Value Meaning
8 Path Computation Monitoring Request (PCMonReq)
9 Path Computation Monitoring Reply (PCMonRep)
The following new PCEP objects are defined in this document.
Object-Class Name
16 MONITORING
Object-Type
1
17 PCE-ID
Object-Type
1
18 PROC-TIME
Object-Type
1
A new Error type for the PCErr message (see [I-D.ietf-pce-pcep]) is
defined in this document (Error-Type and Error-value to be assigned
by IANA).
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Error-type Meaning
11 Performance Monitoring not supported
Error-value
1: Monitoring message not supported by one
of PCEs along the domain path
2: MONITORING object missing in a PCMonReq
message
A new Error-value for the PCErr message Error-types=4 (see
[I-D.ietf-pce-pcep]) is defined in this document (Error-Type and
Error-value to be assigned by IANA).
Error-type Meaning
4 Performance Monitoring Policy violation
3: Monitoring message supported but rejected
due to policy violation
11. Security Considerations
To be addressed in a further revision of this document.
12. Acknowledgements
The author would like to thanks Jean-Louis Le Roux for his useful
comments.
13. References
13.1. Normative References
[I-D.ietf-pce-pcep]
Vasseur, J., "Path Computation Element (PCE) communication
Protocol (PCEP) - Version 1", draft-ietf-pce-pcep-02 (work
in progress), June 2006.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
13.2. Informative References
[I-D.ietf-pce-brpc]
Vasseur, J., "A Backward Recursive PCE-based Computation
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(BRPC) procedure to compute shortest inter-domain Traffic
Engineering Label Switched Paths", draft-ietf-pce-brpc-00
(work in progress), August 2006.
[I-D.ietf-pce-disco-proto-isis]
Roux, J., "IS-IS protocol extensions for Path Computation
Element (PCE) Discovery",
draft-ietf-pce-disco-proto-isis-00 (work in progress),
September 2006.
[I-D.ietf-pce-disco-proto-ospf]
Roux, J., "OSPF protocol extensions for Path Computation
Element (PCE) Discovery",
draft-ietf-pce-disco-proto-ospf-00 (work in progress),
September 2006.
Author's Address
JP Vasseur
Cisco Systems, Inc
1414 Massachusetts Avenue
Boxborough, MA 01719
USA
Email: jpv@cisco.com
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