1 / 10

IETF 62, Minneapolis 03/07/2005

Requirements for PCE Discovery draft-leroux-pce-discovery-reqs-00.txt Jean-Louis Le Roux (France Telecom) Paul Mabey (Qwest) Eiji Oki (NTT) Ting Wo Chung (Bell Canada) Raymond Zhang (BT Infonet). IETF 62, Minneapolis 03/07/2005.

kevina
Download Presentation

IETF 62, Minneapolis 03/07/2005

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Requirements for PCE Discoverydraft-leroux-pce-discovery-reqs-00.txt Jean-Louis Le Roux (France Telecom)Paul Mabey (Qwest)Eiji Oki (NTT) Ting Wo Chung (Bell Canada) Raymond Zhang (BT Infonet) IETF 62, Minneapolis 03/07/2005

  2. Where this ID fits in with the PCE Charter • This draft lists a set of functional requirements for an automatic discovery of PCEs • No assumption on the protocol(s) that could be used • From PCE Charter and milestones : "Specification of techniques in support of PCE discovery within and across domains. -Feb 05  Submit first draft of PCE discovery requirements and protocol extensions documents"

  3. Problem Statement • A PCC may have to be aware of a potentially large number of PCEs • PCEs with distinct capabilities, PCE load balancing, redundancy, PCEs in adjacent domains • Manual PCE configuration may have some limitations • A Potentially huge configuration overhead on each PCC • No discovery of a change in PCE capabilities or that a PCE is no longer alive • Hence a mechanism allowing for Automatic and Dynamic PCE discovery is highly required • Note: No distinction between PCE discovery by PCC or by PCE • A PCE that has to request a path of another PCE can be considered as a PCC

  4. Requirements overview • The PCE Discovery Mechanism MUST allow a PCC • To automatically discover a set of PCEs in its domain • To automatically discover PCEs of other domains that are relevant for inter-domain path computation purpose • MUST allow learning information about a set of PCE capabilities • MUST allow detecting a new PCE or when a PCE capability has changed

  5. Area 5 Area N Area 4 Area 1 Area 3 Area 2 Application Example • Multi-area network with 1 backbone area and N areas • Multi-area TE-LSP placement with inter-PCE communication • PCE function distributed on several ABRs • Potentially a large number of PCEs in the backbone area • Manual config would lead to the configuration of N PCEs per PCC… • (N can be > 50 in operational networks) • Automatically PCE Discovery => Each PCC discovers all PCEs ABR * * * * ABR acting as PCE * Area 0 * * * R1 R2 * * *

  6. Detailed requirements 1/3 • Discovery of PCE location • IP address (v4 or V6) to be used to reach the PCE => Typically a loopback address always reachable • Discovery of PCE capabilities: • Path related capabilities • Capability to compute MPLS-TE, GMPLS paths • Link/Path constraints that can be handled • Supported optimization criteria • Support for backup path computation • … • Path Computation Scope: intra-area, inter-area, inter-AS • Domain IDs : Area IDs, AS Numbers… • Path computation power • …

  7. Detailed requirements 2/3 • Discovery of backup PCEs • A PCE may indicate a backup PCE to be used in case of failure • This would ease the backup selection procedure • Control of the Scope of Discovery, on a per PCE basis • MUST allow controlling to which PCC or group of PCCs the information related to a PCE will be advertised • All PCCs in a single IGP area, • All PCCs in a single AS • A set of one or more PCCs in a set of one or more ASs • … • MUST support discovery across areas and AS boundaries

  8. Detailed requirements 3/3 • PCE Discovery Information Synchronization • Detect any change in PCE capabilities • Detect a new PCE • Time scale for such detection : Within 60s • A specific PCE selection algorithm should be defined • Ensure consistency in computation load balancing behavior • Detailed requirements are beyond the scope of this doc • Scalability with an increase of : • Number of PCCs • Number of PCEs • Number of IGP areas in the discovery scope • Number of ASs in the discovery scope

  9. Remaining issues • Address received comments • Need to improve the security section, particularly for inter-AS PCE discovery • Secured PCE discovery • Identity of any PCE can only be learnt by authorized PCC • Discovery of dynamic parameters such as the PCE CPU state ? • Would improve PCE selection and load balancing • Need to control the frequency of such advertisements • What about PCE aliveness detection ? • Should belong to the PCE discovery procedure? • Should belong to the PCC-PCE communication? • Both?

  10. Next Steps • Interest for this work ? • Consensus for a WG doc ? • Please send your comments to the PCE mailing list

More Related