CCAMP draft-fredette-lmp-wdm-01.txt

[Andre Fredette <fredette@photonex.com>]

NAME OF I-D:

   http://www.ietf.org/internet-drafts/draft-fredette-lmp-wdm-01.txt


SUMMARY

This work is motivated by two main issues.  The first is the need to enhance
the fault detection and recovery support for photonic switches (PXCs), and
the second is to enhance the discovery of link characteristics for optical
networks in general.

GMPLS is being developed to allow networks consisting of photonic switches
(PXCs), optical crossconnects (OXCs), routers, switches and optical line
systems (OLS) (or DWDM systems) to use an MPLS-based control plane to
dynamically provision resources and to provide network survivability using
protection and restoration techniques. As part of this protocol suite, the
Link Management Protocol (LMP) [LMP] is defined to "maintain control channel
connectivity, verify component link connectivity, and isolate link, fiber,
or channel failures within the network."  In it's present form, [LMP]
focuses on peer communications (e.g., OXC-to-OXC).  In this document we
propose extensions to LMP for use with optical line systems.  These
extensions allow the OLS to inform attached devices, such as routers or
PXCs, of (1) link properties needed for routing/signalling and (2) link
failures that can be used to drive failure recovery protocols.


RELATED DOCUMENTS

http://www.ietf.org/internet-drafts/draft-ietf-mpls-lmp-02.txt
http://www.ietf.org/internet-drafts/draft-sahay-ccamp-ntip-00.txt


WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK

lmp-wdm fits in the Control part of the sub-ip work.


WHY IS IT TARGETED AT THIS WG

lmp-wdm enhances the ability of circuit switches and routers using
MPLS-based control protocols to dynamically discover link properties and to
learn about link status.  The link properties can be useful during
signalling of paths, and the link status information is essential for fault
detection and recovery.  Furthermore, lmp-wdm is independent of any
signalling protocol, so it can be used by both distributed control system,
such as GMPLS, and centralized management systems.

Therefore, lmp-wdm supports the following CCAMP objectives:

- Define signalling protocols and measurement protocols such that they
support multiple physical path and tunnel technologies (e.g., O-O and O-E-O
optical switches, ATM and Frame Relay switches, MPLS, GRE) using input from
technology-specific working groups such as MPLS, IPO, etc.

- Define signalling and measurement protocols that are independent of each
other. This allows applications other than the signalling protocol to use
the measurement protocol; it also allows the signalling protocol to use
knowledge obtained by means other than the measurement protocol.

- Abstract link and path properties needed for link and path protection.
Define signalling mechanisms for path protection, diverse routing and fast
path restoration. Ensure that multi-layer path protection and restoration
functions are achievable using the defined signalling and measurement
protocols, either separately or in combination.

- Define how the properties of network resources gathered by the measurement
protocol can be distributed in existing routing protocols, such as OSPF and
IS-IS.


JUSTIFICATION

draft-fredette-lmp-wdm-XX.txt (lmp-wdm) is a protocol proposal intended to
satisfy the optical link interface (OLI) requirements
(draft-many-oli-reqts-00.txt - described separately).  lmp-wdm has been
discussed in the past two ccamp sessions and a competing proposal,
draft-sahay-ccamp-ntip-00.txt (ntip), was discussed in the last one.  There
has been a great deal of interest in this work by both network operators and
vendors.  We are planning to submit a joint requirements document (lmp-wdm
co-authors, ntip co-authors, and others).  We are also trying to develop a
consensus between the co-authors of the two competing proposals (and
others).  If a consensus is reached before the next meeting, then we expect
that a single joint draft will be submitted instead of this one.  However,
if no consensus can be reached, we beleive that this work is too important
to let languish, so we plan to update draft-fredette-lmp-wdm-01.txt as
needed to meet the jointly agreed-upon requirements.