RE: Path Computation Element (PCE) BOF

All,

Please review and comment on "Path Computation Element (PCE) Problem
Statement"
http://www.ietf.org/internet-drafts/draft-ash-pce-problem-statement-00.t
xt.  The PCE is an approach to MPLS traffic engineering that is
applicable to inter-area and inter-AS path computation.  A problem
statement and overview of solution alternatives is provided.  This will
be discussed during the PCE BOF outlined below.

Thanks,
Jerry=20

________________________________

From: [email protected] [mailto:[email protected]] On
Behalf Of Adrian Farrel
Sent: Thursday, June 17, 2004 5:01 PM
To: [email protected]; '[email protected]'; [email protected];
[email protected]; TEWG
Cc: 'Jean Philippe Vasseur'
Subject: Path Computation Element (PCE) BOF

Hi,
=20
We will be holding a BOF in San Diego under the care of the Routing
Area.
=20
Please see the description, a draft agenda, and proposed charter below.
=20
We'd welcome any thoughts for additions to the agenda, and any pointers
to existing drafts that you consider already fit within this scope.
=20
If you have views for or against, please bring them to the BOF where we
will hopefully have time to air them fully.
=20
Thanks,
Adrian and JP
=20
=3D=3D=3D=3D
Path Computation Element BOF (PCE BOF) Agenda
60th IETF, San Diego, August 2004
=20
Routing Area Ads: Alex Zinin ([email protected] <mailto:[email protected]> ),
                  Bill Fenner ([email protected]
<mailto:[email protected]> )

BOF Chairs: JP Vasseur ([email protected] <mailto:[email protected]>
),
            Adrian Farrel ([email protected]
<mailto:[email protected]> )

Description:
In certain MPLS TE networks it may be beneficial or desirable to have
path=20
computation performed by a distinct node (termed the Path Computation=20
Element  PCE) that is not the LSR that needs to know the path. This BOF=20
examines the scope of such function, what extensions to existing
protocols=20
might required, what additional protocols may need to be developed, and=20
whether there is cuase and support for this work within the IETF.

---

Proposed BOF agenda
1) Introduction, admin, statement of objectives of the BOF (10 minutes)
2) Overview of PCE-based LSP Path computation (10 minutes)
         - terminology
         - dichotomy (centralized versus distributed, statefull versus=20
           stateless, ...)
3) Requirements for PCE-based path computation (5 minutes)
         - for intra-area TE LSP (packet and non packet LSP, multiple=20
           criteria optimization techniques, online/offline)
         - for inter-area and inter-AS TE (shared information or=20
           collaborative computation)
4) Functional requirements of a PCE-based path computation system  (10
minutes)
         - Framework,
         - Path computation model
         - discovery of PCEs within a network
         - distribution of TE information to PCEs
         - LSR-PCE communication
         - Monitoring and Management (MIBs)
         - Policy/Security/Confidentiality in the context of
inter-providers
5) Current status of drafts and early implementations (10 minutes)
6) Why should this be IETF work? (5 minutes)
         - CCAMP or new Working Group?
         - Is this work limited to MPLS-TE? What about BGP route
servers?
7) Proposed charter (see below) (10 minutes)
8) Open discussion (50 minutes)
9) Summary and conclusions (10 minutes)

---

Proposed WG Charter
=20
Organizational Overview
The PCE working group coordinates the work within the IETF of defining
the=20
operation of path computation elements within the Internet. Path=20
computation elements are responsible for computing paths through IP=20
networks for uses such as traffic engineering so that a prime consumer
of=20
such paths might be an MPLS-TE LSR. Areas of responsibility will include

the collection of attributes relevant to the computation of paths, the=20
discovery by LSRs of available path computation elements, the
communication=20
with LSRs for the request of path computation, the collaboration between

path computation elements within the network, and analysis of path=20
computation algorithms with a view to ensuring consistency between
computed=20
paths. The working group will work closely with many working groups in
the=20
Routing Area including the OSPF, IS-IS, IDR, MPLS and CCAMP working
groups.

Working Group Scope
The PCE working group scope includes:
- Definition  of Generalized Traffic Engineered LSP paths computation=20
  techniques involving Path Computation Element(s). This includes the
intra=20
  IGP area, inter IGP area, inter-AS and inter-provider TE LSPs path=20
  computation for Point-to-Point, Point-to-Multipoint and=20
  Multipoint-to-Multipoint TE LSPs.
- Definition of protocol-independent metrics and constraints defining
path=20
  quality measurement criteria, algorithm complexity and scalability
criteria=20
  related to path computation techniques.
- Definition of requirements for communication between LSRs and PCEs=20
  including routing extensions in support of PCE discovery techniques
within=20
  an IGP area and across multiple IGP areas, ASes and Provider networks,
and=20
  including the development of new protocols or protocol extensions for=20
  requesting path computation and supplying responses. Any protocol=20
  extensions will developed in conjunction with the working groups in
charge=20
  of the specific protocols.
- Specification of routing (OSPF, ISIS, BGP) and signalling extensions=20
  (RSVP-TE) required by PCE-based path computation techniques. The
extensions=20
  will developed in conjunction with the working groups in charge of the

  specific protocols.
- Specification of requirements and protocol extensions related to the=20
  policy, security and confidentiality aspects of PCE-based path
computation=20
  techniques involving PCEs of multiple Providers.
- Definition of MIBs, management procedures related to the protocol=20
  extensions defined by the WG

In doing this work, the WG will closely work with at least the following

other WGs: CCAMP, MPLS, ISIS, OSPF, IDR. The WG will also cooperate with

the ITU-T and OIF.

Goals and Milestones

Dates for milestones to be decided later.

  Post strawman WG goals and charter.

  Submit WG document defining the framework and applicability of the=20
  PCE model.

  Select a single candidate protocol from communication between LSRs=20
  and PCEs.

  Submit document(s) that define various path computation models
=20
  Submit an analysis document examining the requirements for coherent
  computation techniques and the implication of cooperation between=20
  PCEs.

  Submit a document defining the protocol for communication between=20
  LSRs and PCEs.

  Submit document(s) defining extensions to routing and signalling=20
  protocols necessary to support the use of a PCE model within MPLS
  networks.
=20
  Submit a document defining MIB modules for modeling and management=20
  of PCE systems.