Subject: Infomral status presented to ITU

From: "Adrian Farrel" <[email-masked]>
Date: Thu, 29 Jun 2006 09:54:59 +0100

Hi,

I am at the Study Group 15, Question 14 interim meeting, and I was asked to 
present the status of IETF work related to the control plane for optical 
networks.

Below is my text. Note that is was not a formal liaison, but an informal 
communication.

Thanks,
Adrian

===

Introduction

In response to several requests, this contribution provides an interim and 
unofficial status of the activities within the IETF that are pertinent to 
optical networking.

Overview

Work continues to progress within the IETF in many working groups that are 
relevant to the activities of Study Group 15. Of most direct relevance to 
Question 14/15 are the activities in the Common Control and Measurement 
Plane (CCAMP) working group, the Path Computation Element (PCE) working 
group, and the Layer One Virtual Private Network (L1VPN) working group.

CCAMP is responsible for the development and maintenance of the GMPLS family 
of protocols including signaling extensions for RSVP-TE, and routing 
extensions for OSPF and IS-IS. It also looks after LMP and LMP-WDM. CCAMP is 
also working on the frameworks and protocol extensions for multi-domain and 
multi-layer networks.

The PCE working group is developing the architecture, requirements, 
protocols, and applicability for the Path Computation Element - a functional 
element responsible for determining paths (routes) that may span multiple 
domains.
The L1VPN working group is responsible for the development of GMPLS protocol 
extensions and applicabilities in support of a service model that involves 
the supply by a service provider of layer one connectivity between customer 
sites.

Recent Activity

Control of TDM Switches

a.       Revision of RFC 3946

RFC 3946 is titled Generalized Multi-Protocol Label Switching (GMPLS) 
Extensions for Synchronous Optical Network (SONET) and Synchronous Digital 
Hierarchy (SDH) Control. This RFC was published in October 2004, is stable, 
has been implemented by multiple vendors, and is deployed with live traffic. 
Recent exchanges with the OIF exposed some issues of clarity, and a minor 
editorial revision (equivalent to an
Amendment within the ITU-T) was published as 
draft-ietf-ccamp-rfc3946-bis-01.txt in December 2005. This draft has now 
been fully reviewed by the IETF community and has been accepted for 
publication as an RFC. It is expected that it will be published within the 
next few months.

b.      Diversely routed VCAT groups

RFC 3946 provides mechanisms for establishing and maintaining LSPs in 
support of virtual concatenation where the members of a VCG are co-routed; 
that is, where all group members follow the same path through the network. 
Recently, hardware vendors have become confident in their technical 
solutions to support diversely routed VCG members and have asked for 
protocol solutions to be developed. Members of the CCAMP working group are 
currently specifying the requirements for this work including the use of 
LCAS, and it is anticipated that this will soon become official CCAMP work. 
The development of appropriate protocol solutions has already been discussed 
and will most likely follow quickly after the requirements work.

ASON Signaling

a.       Requirements

Following from the completion of RFC 4139 (Requirements for Generalized MPLS 
(GMPLS) Signaling Usage and Extensions for Automatically Switched Optical 
Network (ASON)) which was the product of successful cooperation and liaison 
between SG15 and CCAMP, CCAMP has also published RFC 4397 (A Lexicography 
for the Interpretation of Generalized Multiprotocol Label Switching (GMPLS) 
Terminology within the
Context of the ITU-T's Automatically Switched Optical Network (ASON) 
Architecture).

RFC 4397 required extensive liaisons, discussion, and face-to-face meetings 
before both the CCAMP working group and SG15 were satisfied with its 
contents. This RFC provides the tools necessary to assess the GMPLS 
signaling protocol RFCs and determine how they may be used to satisfy the 
requirements set out in RFC 4139.

b.      Toolkit

The CCAMP working group has just completed work on an important item in the 
protocol toolkit. Although not aimed directly at the ASON environment, 
draft-ietf-ccamp-gmpls-rsvp-te-call (Generalized MPLS (GMPLS) RSVP-TE 
Signaling Extensions in support of Calls) has clear applicability to ASON. 
This work has completed working group last call and will receive a few minor 
editorial changes before advancing for wider IETF review and publication as 
an RFC.

c.       Solutions

The CCAMP working group believes that all building blocks are now in place 
to use GMPLS signaling protocols to satisfy the ASON signaling requirements 
as expressed in RFC 4139. In particular, this includes the provision of 
signaling at the UNI, E-NNI, and I-NNI. CCAMP will soon start work on an 
Applicability Statement to document how the requirements are met, and it is 
anticipated that this will be liaised to Q14/15 as work in progress.

d.      Inter-working

CCAMP recognizes that an important concern for some people is how they can 
achieve inter-working of G.7713.x (x = 1, 2, or 3) or OIF UNI reference 
points on either side of a domain where the I-NNI is achieved using GMPLS 
signaling protocols. Clearly this needs to be achieved using a standardized 
approach so that I-NNI nodes will not be disrupted, and so that UNI-N 
implementations can cooperate. It is also CCAMP's intention to produce an 
Applicability Statement for this situation, and it is anticipated that this 
work will be liaised to Q14/15 as work in progress.

ASON Routing

a.       Requirements

RFC 4258 (Requirements for Generalized Multi-Protocol Label Switching 
(GMPLS) Routing for the Automatically Switched Optical Network (ASON)) is 
the best evidence we have that the IETF, ITU-T, and OIF communities can work 
together. This document, finally published in November 2005, concentrates on 
the routing requirements placed on the GMPLS suite of protocols in order to 
support the capabilities and functionalities of an Automatically Switched 
Optical Network (ASON) as defined by the ITU-T. It was produced by a joint 
team of people from (although not representing) there three bodies, and was 
agreed only after careful liaison with Q14/15.

b.      Evaluation of Existing Routing Protocols

draft-ietf-ccamp-gmpls-ason-routing-eval was also a collaborative effort 
and, as well as experts from the OIF and SG15, the team included IETF 
routing protocol experts. The draft which has been reviewed by the IESG and 
the IETF community, and is ready for publication as an RFC, examines the 
requirements set out in RFC 4258 and compares them against the capabilities 
of the IETF routing protocols. Some small lacunae are identified as 
requiring protocol extensions.

c.       Solutions

Design of the necessary protocol extensions to complete a solution that 
meets the requirements laid out in RFC 4258 (i.e. to supply the missing 
pieces identified in draft-ietf-ccamp-gmpls-ason-routing-eval) is well 
progressed in the IETF. draft-dimitri-ccamp-gmpls-ason-routing-sol-01 
published in March proposes protocol solutions, and has just been split into 
separate work items for OSPF and IS-IS. Discussions are well advanced with 
the appropriate IGP working groups so that CCAMP will be able to adopt this 
work soon, and we have received indications that the OIF is looking to the 
completion of this work in order to determine a final E-NNI routing 
solution.

d.      PCE

The Path Computation Element (PCE) is receiving attention in Q14/15 through 
the work on G.7715.2. The PCE working group has made good advances in the 
determination of an architecture and requirements statements. These have 
completed work in the working group and have been reviewed by the IESG.
While work continues to develop a suitable communications protocol for path 
queries, the working group is also examining the applicability of PCE to 
inter-layer scenarios. Some clarification  from SG15 of whether such 
scenarios are within the scope of the ASON model may be beneficial to the 
work in the PCE working group.

Control-Plane / Management-Plane Migration

A recent liaison from SG15 to CCAMP highlighted some of the problems with 
the concept of migrating an existing LSP between the control plane and the 
management plane. This has proven to be extremely useful to CCAMP members in 
developing a concise set of requirements for this function within specific 
and limited environments. There appears to be significant support from 
carriers for this work, and it is likely to progress within the CCAMP 
working group first as a requirements statement and then with the addition 
of simple signaling protocol extensions.

Future Cooperation

The CCAMP working group co-chairs plan to send a formal liaison to SG15 to 
communicate about CCAMP progress shortly after the IETF meeting that will be 
held in Montreal at the start of July.

The CCAMP, L1VPN and PCE working groups always welcome questions and 
contributions from all sources on their mailing lists which have open access 
to everyone. More substantial contributions are welcomed in the form of 
Internet-Drafts.