CCAMP WG - http://www.ietf.org/internet-drafts/draft-bellato-ccamp-g709-framework-00.txt

[Dimitri Papadimitriou <dimitri.papadimitriou@alcatel.be>]

NAME OF I-D:

http://www.ietf.org/internet-drafts/draft-bellato-ccamp-g709-framework-00.txt

SUMMARY

In this document, we describe the G.709 Digital and Optical Transport 
Hierarchies (OTH) defined at the ITU-T and the relationships with the 
GMPLS architecture specification [GMPLS-ARCH]. This in order to specify 
how current GMPLS Signalling specification [GMPLS-SIG] can be
accommodated 
in order to encompass these hierarchies to extend GMPLS signalling for
OTN.
More specifically we detail the concepts that are included in the GMPLS 
G.709 Signalling document (draft-fontana-ccamp-gmpls-g709.txt).

RELATED DOCUMENTS

http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-architecture-00.txt 
http://www.ietf.org/internet-drafts/draft-ietf-mpls-generalized-signalling-04.txt
http://www.ietf.org/internet-drafts/draft-ietf-mpls-generalized-rsvp-te-03.txt
http://www.ietf.org/internet-drafts/draft-ietf-mpls-generalized-cr-ldp-03.txt
http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-sonet-sdh-01.txt
http://www.ietf.org/internet-drafts/draft-fontana-ccamp-gmpls-g709-00.txt
http://www.ietf.org/internet-drafts/draft-gasparini-ccamp-gmpls-g709-ospf-isis-00.txt

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

It fits in the CCAMP WG - Control C (in this case control of Optical
Transport Networks)

WHY IS IT TARGETED AT THIS WG
 
The work is intended to complete the transmission plane technology
controlled by GMPLS signalling protocols in order to accommodate 
the G.709 Optical Transport Networks (OTN). 
 
JUSTIFICATION
 
Recently, the ITU-T finalized the first version of the Optical
Transport Networks (OTN) standardization [ITUT-G709] to provide the
transparent digital pipe (digital wrapper) to be transported into
optical channels.

The OTN provides two fundamental degrees of flexibility: in terms of
wavelength and in terms of bandwidth transmission optimization
without losing the integrity of the lower bit rates pipes filled by
the access network. From that perspective, the OTN specification
enables as well the control of all-optical sub-networks.

However, the OTN architecture has today no explicit association with
any IP-based control plane, without which the future deployment of
OTN equipment is clearly uncertain. Therefore, [ITUT-G709] foresees
a strong requirement for future evolutions that can provide explicit
support for the OTN control layer. Requirements for the definition
of the OTN control plane (also referred to as Automatic Switched
Transport Network – ASON) are currently under definition at the ITU-T.

Consequently, Generalized MPLS (GMPLS) as specified in [GMPLS-SIG],
can more than certainly provide the efficient "control-plane
service" needed by the OTN specifications. Moreover, GMPLS can give
fundamental indications in terms of how OTN can be controlled and
where some additional features have to added (if needed) at the
optical transmission layer level, in order to hit the goal of
intelligent optical networks.

Today, GMPLS efforts are directed in extending IP well known
technology to control and manage lower non-packet based layered
networks. Using the same framework and the same kinds of signalling
and routing protocols suite to control multiple layers will not only
reduce the overall complexity of designing, deploying and maintaining 
OTN networks but also allow potentially two contiguous layers to 
inter-operate when using either an overlay, an augmented or a peer 
model. In the mean time, GMPLS is very suitable for controlling each 
layer completely independently.

Moreover, GMPLS can provide new capabilities and features for OTN
such as flexible and distributed LSP establishment (today performed
through the use of centralized Network Management Systems - NMS),
multi-layer circuit establishment and GMPLS-based restoration
methods that are of paramount importance for operators and carriers.