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<CCAMP> <draft-krishnaswamy-optical-rsvp-extn-00.txt>
NAME OF ID:
http://www.ietf.org/internet-drafts/draft-krishnaswamy-optical-rsvp-extn-00.
txt
SUMMARY
We propose an extension to RSVP-TE that would permit setting up
OCh (optical channel) connections whose paths form a topology that is
independent of the control layer topology. This separation of an OCh
connection path and the associated control layer network may be
necessary for many reasons. First, it may not be possible to provide
a control channel connection to each one of an optical network
element (ONE)'s neighbor - for many reasons explained in Sec. 2.
Secondly by providing the means to signal OCh connections
through different multiple control paths, we achieve network
resilience against control channel failure. We propose a new
extension to RSVP-TE called Lightpath Route Object (LRO) which is a
list of nodes along OCh connection path. This is carried in the Path
message by RSVP-TE as an Opaque Object for interpretation and use by
the optical nodes. This facilitates setting up OCh connections
between nodes that have no adjacency at the IP layer.
Mechanisms like LSP hierarchy which enables creation of a new IP
forwarding adjacency based on LSP tunnels is not a scalable
architecture for large optical networks. Bidirectional LSPs need to
be setup for each new IP adjacency (and advertised by IGP) before we
can setup lightpath LSPs. Issues like latency in lightpath connection
setup (due to the need to setup LSP tunnels first), establishing and
maintaining hierarchical LSPs etc. are other factors that make this
approach unsuitable for large optical networks. As a matter of
implementation, most optical networks are provisioned by
point-n-click method and incorporating mechanisms to setup multiple
LSP tunnels for each lightpath setup would make the automation
difficult.
RELATED DOCUMENTS
http://www.ietf.org/internet-drafts/draft-ietf-mpls-rsvp-lsp-tunnel-08.txt
http://www.ietf.org/internet-drafts/draft-ietf-mpls-generalized-signaling-04
.txt
http://www.ietf.org/internet-drafts/draft-ietf-mpls-lsp-hierarchy-02.txt
WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK
CCAMP
C (control)
MPLS
WHY IS IT TARGETED AT THIS WG
This work proposes extensions to an existing signaling protocol
(RSVP-TE) to enable setting up OCh connections (path dis-joint from
control layer) using MPLS technology. Hence it is clear that the scope
of this work is within the charter of the CCAMP WG.
JUSTIFICATION
CCAMP is chartered to work on signaling protocols such that they can
support setting up OCh connections in optical networks. GMPLS
Signaling Functional Description draft enables specifying desired
connection parameters. What we feel is missing is the ability to
specify the full lightpath list (which may not have IP forwarding
adjacency) and mechanisms to establish such a connection. This will
enable a true separation of control and data plane topology, a
necessity in large optical networks.