Unanswered Questions in the Path Computation Element Architecture
RFC 7399
Internet Engineering Task Force (IETF) A. Farrel
Request for Comments: 7399 Juniper Networks
Category: Informational D. King
ISSN: 2070-1721 Old Dog Consulting
October 2014
Unanswered Questions in the Path Computation Element Architecture
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 (VNTM) in
RFC 5623 and generalized to Hierarchical PCE (H-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 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.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7399.
Farrel & King Informational [Page 1]
RFC 7399 Questions in PCE Architecture October 2014
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described in the Simplified BSD License.
Farrel & King Informational [Page 2]
RFC 7399 Questions in PCE Architecture October 2014
Table of Contents
1. Introduction ....................................................3
1.1. Terminology ................................................4
2. What Is Topology Information? ...................................4
3. How Is Topology Information Gathered? ...........................5
4. How Do I Find My PCE? ...........................................6
5. How Do I Select between PCEs? ...................................7
6. How Do Redundant PCEs Synchronize TEDs? .........................8
7. Where Is the Destination? .......................................9
8. Who Runs or Owns a Parent PCE? .................................10
9. How Do I Find My Parent PCE? ...................................11
10. How Do I Find My Child PCEs? ..................................11
11. How Is the Parent PCE Domain Topology Built? ..................12
12. Does H-PCE Solve the Internet? ................................12
13. What are Sticky Resources? ....................................13
14. What Is a Stateful PCE for? ...................................14
15. How Is the LSP-DB Built? ......................................14
16. How Do Redundant Stateful PCEs Synchronize State? .............15
17. What Is an Active PCE? What Is a Passive PCE? .................16
18. What is LSP Delegation? .......................................17
19. Is an Active PCE with LSP Delegation Just a Fancy NMS? ........18
20. Comparison of Stateless and Stateful PCE ......................18
21. How Does a PCE Work with a Virtual Network Topology? ..........19
22. How Does PCE Communicate with VNTM ............................21
23. How Does Service Scheduling and Calendering Work? .............21
24. Where Does Policy Fit In? .....................................22
25. Does PCE Play a Role in SDN? ..................................23
26. Security Considerations .......................................23
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