Hi Adrian, Very interesting and useful draft.
A few small comments from me for discussion. (1) What Is Topology Information? Should SRLG/SRG information be mentioned? (2) Does H-PCE Solve The Internet? It is obviously that the answer is "NO". However, another question could be addressed: how many domains and how many levels (hierachical levels) can be handled by H-PCE? (3) What Is A Stateful PCE For? It says: "A Stateful PCE maintains a database of LSPs that are active in the network (the LSP-DB). This database allows a PCC to refer to an LSP using only its identifier - all other details can be retrieved by the PCE from the LSP-DB.". What do you mean for *active LSPs* here? Could a protecting LSP be regarded as *active* when it is not in the Operational state? Scheduling LSPs (in question 22) are active or not? (4) Is An Active PCE with LSP Delegation Just a Fancy NMS? I agree that in many ways the answer here is "yes", especially from the function perspective. When NMS is doing this "delegation" as it has been done in the real deployment, there is no need to do the "delegation" in a per-LSP way. So my question is: when an active PCE is used to do the delegation function, is it necessary in a per-LSP way? Or it could be done in the *NMS* way? (5) Where Does Policy Fit In? I think if [RFC5394] is used to set up the policies as much as possible, it can reduce many PCEP extensions to make PCE just focus on *computation*. Best Regards Fatai -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Adrian Farrel Sent: Friday, January 18, 2013 12:46 AM To: [email protected] Subject: [Pce] Ramblings of two old dogs Hi, Over the years Dan and I have been asked a number of questions about PCE and how it fits into different uses in the network. Although we feel that the ABNO document (draft-farrkingel-pce-abno-architecture) goes a long way to explain the bigger picture, there are a lot of smaller, everyday questions that need attention. In an attempt to reduce the email we see, we have collected these into an Informational I-D as below. Obviously, if you all send us comments and thoughts on this document you will successfully thwart our plans :-) Adrian and Dan > -----Original Message----- > From: [email protected] [mailto:[email protected]] > On Behalf Of [email protected] > Sent: 17 January 2013 15:30 > To: [email protected] > Subject: I-D Action: draft-farrkingel-pce-questions-00.txt > > > A New Internet-Draft is available from the on-line Internet-Drafts directories. > > > Title : Unanswered Questions in the Path Computation Element > Architecture > Author(s) : Adrian Farrel > Daniel King > Filename : draft-farrkingel-pce-questions-00.txt > Pages : 22 > Date : 2013-01-17 > > Abstract: > The Path Computation Element (PCE) architecture is set out in RFC > 4655. The architecture is extended for multi-layer networking with > the introduction of the Virtual Network Topology Manager in RFC > 5623, and generalized to Hierarchical PCE in RFC 6805. > > These three architectural views of PCE deliberately leave some key > questions unanswered especially with respect to the interactions > between architectural components. This document draws out those > questions and discusses them in an architectural context with > reference to other architectural components, existing protocols, and > recent IETF work efforts. > > This document does not update the architecture documents and does not > define how protocols or components must be used. It does, however, > suggest how the architectural components might be combined to provide > advanced PCE function. > > > The IETF datatracker status page for this draft is: > https://datatracker.ietf.org/doc/draft-farrkingel-pce-questions > > There's also a htmlized version available at: > http://tools.ietf.org/html/draft-farrkingel-pce-questions-00 > > > Internet-Drafts are also available by anonymous FTP at: > ftp://ftp.ietf.org/internet-drafts/ > > _______________________________________________ > I-D-Announce mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/i-d-announce > Internet-Draft directories: http://www.ietf.org/shadow.html > or ftp://ftp.ietf.org/ietf/1shadow-sites.txt _______________________________________________ Pce mailing list [email protected] https://www.ietf.org/mailman/listinfo/pce _______________________________________________ Pce mailing list [email protected] https://www.ietf.org/mailman/listinfo/pce
