Hi all, Here are the changes in this new revision:
-The discovery of the Objective Functions (OF) supported by a PCE used to rely on the PCED TLV carried in ISIS/OSPF. Actually for scalability reasons, the OSPF/ISIS PCED TLV has been closed, and no new sub-TLVs can be added, so we can no longer rely on the PCED TLV for OF discovery. Following the requirements set forth in RFC 4657 & 4674, and as OF can be considered as a detailed capability, its discovery could rely on PCEP. For that purpose we moved OF discovery from ISIS/OSPF to PCEP. A new PCEP TLV has been defined, the OF-List TLV, to be carried within the Open object. This allows discovering the OF supported by a PCE during session setup phase. -We factorized the transport of the OF in a PCRep for a synchronized computation: "When the PCE wants to indicate to the PCC the objective function that was used for the synchronized computation of a set of paths, the PCRep message MUST include the corresponding SVEC object directly followed by the OF object, which MUST NOT be repeated for each elementary request." -Also we made some rewording for the sake of clarity. Of course your feedback/comments are welcome. Regards, J-L, J-P, Young > -----Message d'origine----- > De : [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Envoyé : lundi 19 novembre 2007 18:15 > À : [EMAIL PROTECTED] > Cc : [EMAIL PROTECTED] > Objet : [Pce] I-D ACTION:draft-ietf-pce-of-01.txt > > A New Internet-Draft is available from the on-line > Internet-Drafts directories. > This draft is a work item of the Path Computation Element > Working Group of the IETF. > > Title : Encoding of Objective Functions in > Path Computation Element communication Protocol (PCEP) > Author(s) : J. Le Roux, et al. > Filename : draft-ietf-pce-of-01.txt > Pages : 17 > Date : 2007-11-19 > > The computation of one or a series of Traffic Engineering Label > Switched Paths (TE LSPs) in MultiProtocol Label Switching > (MPLS) and > Generalized MPLS (GMPLS) networks, is subject to a set of > one or more > specific optimization criteria(s), referred to as an objective > function (e.g. minimum cost path, widest path, etc.). A Path > Computation Element (PCE) may support one or multiple objective > functions, and it is desired for a Path Computation Client > (PCC) to > automatically discover the set of objective functions > supported by a > PCE. Furthermore, it may be useful for a PCC to specify in a path > computation request the required objective function to be > used by the > PCE to compute a TE LSP or a set of TE LSPs. Thus the aim of this > document is to define extensions to the PCE communication Protocol > (PCEP) in order to allow a PCC to discover the set of objective > functions supported by a PCE as well as to allow a PCC to > indicate in > a path computation request the required objective function > and a PCE > to indicate in a path computation reply the objective > function that > was used for path computation. > > A URL for this Internet-Draft is: > http://www.ietf.org/internet-drafts/draft-ietf-pce-of-01.txt > > To remove yourself from the I-D Announcement list, send a > message to [EMAIL PROTECTED] with the word > unsubscribe in the body of the message. > You can also visit https://www1.ietf.org/mailman/listinfo/I-D-announce > to change your subscription settings. > > Internet-Drafts are also available by anonymous FTP. Login > with the username "anonymous" and a password of your e-mail > address. After logging in, type "cd internet-drafts" and then > "get draft-ietf-pce-of-01.txt". > > A list of Internet-Drafts directories can be found in > http://www.ietf.org/shadow.html or > ftp://ftp.ietf.org/ietf/1shadow-sites.txt > > Internet-Drafts can also be obtained by e-mail. > > Send a message to: > [EMAIL PROTECTED] > In the body type: > "FILE /internet-drafts/draft-ietf-pce-of-01.txt". > > NOTE: The mail server at ietf.org can return the document in > MIME-encoded form by using the "mpack" utility. To use this > feature, insert the command "ENCODING mime" before the "FILE" > command. To decode the response(s), you will need "munpack" or > a MIME-compliant mail reader. Different MIME-compliant > mail readers > exhibit different behavior, especially when dealing with > "multipart" MIME messages (i.e. documents which have been split > up into multiple messages), so check your local documentation on > how to manipulate these messages. > > Below is the data which will enable a MIME compliant mail > reader implementation to automatically retrieve the ASCII > version of the Internet-Draft. > _______________________________________________ Pce mailing list [email protected] https://www1.ietf.org/mailman/listinfo/pce
