Hi Pcers,
The revision of the PCE TED alternatives (draft-lee-pce-ted-alternatives-02.txt) is now available: http://www.ietf.org/internet-drafts/draft-lee-pce-ted-alternatives-02.txt Please note the following changes made in the revision based on inputs from many folks. * Global change: IGP -> IGP-TE (per Igor) * Section 1.1 We corrected a statement as follows (per Igor): In OSPF the information directly related to IP connectivity (and hence the control communications plane for all three technologies) and non-IP advertisements are kept in the link state database (LSDB), while information related to traffic engineering used by MPLS and GMPLS is kept in a (conceptually) separate TED which can be considered a subset of the LSDB. * Section 2 (per Igor) We have added a few new paragraphs that discuss cooperation between IGP-TE and an alternative method and some advantages/disadvantages of both models. * Section 2.1 (Per Fabien) Architecture Option 3 has changed to: "Nodes send local information to at least one PCE" from "Nodes send local information to one PCE." This is to avoid a single point of failure. Section 2.1.3 below elaborates two possible ways to implement this option. * Section 2.1.1 (per Fabien) We added a comment on scaling issue to clarify that scaling issue associated with option 1 may be of a real concern if there are only a few PCEs (e.g., two to three PCEs) in the networks. * Section 2.1.3 (per Fabien) We have added a new paragraph: "A number of approaches can be used to ensure control plane resilience in this architecture. (1) Each node can be configured with a primary and a secondary PCE to send its information to; In case of failure of communications with the primary PCE the node would send its information to a secondary PCE (warm standby). (2) Each node could be configured to send its information to two different PCEs (hot standby)." * Section 2.4 (Per Peng He) We elaborated PCE TED maintenance procedure: The PCE is responsible for creating and maintaining the TED that it will use. Key functions include: 1. Establishing and authenticating communications between the PCE and sources of TED information. 2. Timely updates of the TED with information received from nodes, peers or other entities. 3. Verifying the validity of information in the TED,i.e., ensure that the network information obtained from nodes or elsewhere is relatively timely, or not stale. By analogy with similar functionality provided by IGPs this can be done via a process where discrete "chunks" of TED information are "aged" and discard when expired. This combined with nodes periodically resending their local TE information leads to a timely TED. * Section 3.2 and Appendix We deleted Section 3.2 and the appendix that discuss the protocol and implementation details. Thus this draft stays as the framework/requirement draft. We will address protocol enhancements as separate drafts once this work is accepted as the WG draft. (Per Dan King) * We have added a few contributors. We'd appreciate your comments and further discussion on this draft. Best Regards, Young & Greg
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