Technical Summary
A Stateful Path Computation Element (PCE) maintains information on the
current network state including existing Traffic Engineered (TE) Label
Switched Path (LSPs). This information may be considered when computing
path for new TE LSPs.
The Hierarchical Path Computation Element (H-PCE) architecture allows the
optimum sequence of inter-connected domains to be selected for a multi-domain TE LSP.
This document describes general considerations and use cases for the deployment
of Stateful PCEs using the Hierarchical PCE architecture.
Working Group Summary
The working group process was "steady." The document was adopted two years ago
and has progressed slowly with small updates and direction from the WG mainly
off-list.
As an applicability statement, the WG supported the idea of the work (the adoption
poll attracted support from ten non-authors), but didn't seem to put in much effort
to advance the work, preferring to watch the authors write the text.
WG last call had several constructive comments of support that included reasoning,
and also a couple of helpful reviews.
But there were no issues with consensus.
Document Quality
There are several research implementations of stateful hierarchical PCEs
confessed to separately by two network operators, an equipment vendor,
and a few universities. As such, this document provides a base reference
for how to put the concepts together in a meaningful way.
No special reviewing was necessary.