CCAMP draft-mannie-ccamp-gmpls-lbm-tdm-00.txt

["Mannie, Eric" <Eric.Mannie@ebone.com>]

Dear All,

Please find hereafter a summary of a new internet-draft. I sent it for
publication today and it should be available soon on the IETF Web site.

NAME OF I-D

draft-mannie-ccamp-gmpls-lbm-tdm-00.txt

SUMMARY

   This document defines how GMPLS can be used to dynamically modify 
   the bandwidth of a TDM circuit. It focuses first on SONET/SDH and 
   will cover G.709 in a next version. 
    
   SONET/SDH Bandwidth modification can be indeed achieved in very 
   different ways. It can be done by establishing another circuit 
   between the same source and destination with different 
   characteristics (e.g. signal type) and then by switching the 
   traffic to that new circuit doing a switchover. 
    
   At the other end of the spectrum, bandwidth modification can be 
   done by dynamically adding or removing SPEs/VCs to a circuit using 
   the concept of virtual or contiguous concatenation. This is 
   ideally achieved in a non-disruptive way and by avoiding double 
   counting (i.e. double reserving) the resources while modifying the 
   bandwidth, by using the concept of make-before-break. This 
   specification focuses on this last case. 
    
   Bandwidth modification is in practice easier to do when virtual 
   concatenation is used since SPEs/VCs don't need to be contiguous, 
   are transported individually and can even be routed independently.  
    
   This can be achieved as well when contiguous concatenation is used 
   but is in practice less likely to happen since a bandwidth 
   increase requires additional free SPEs/VCs physically contiguous 
   at the end of the circuit. 
    
   This specification also defines how to use multiple differently 
   routed LSPs to build a single SONET/SDH virtually concatenated 
   circuit. Each LSP can be protected/restored individually. 

RELATED DOCUMENTS

http://search.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-sonet-sdh-02.t
xt
http://search.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-architecture-0
0.txt

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

In the CCAMP WG, with the GMPLS signaling.

WHY IS IT TARGETED AT THIS WG

Because it is a proposed signaling extension to the GMPLS signaling to allow
LSP bandwidth modification in the TDM case. It addresses the charter in the
same way as the GMPLS signaling.

JUSTIFICATION

This draft defines straightforward signaling mechanisms and extensions that
can be used in the GMPLS signaling to dynamically modify the bandwidth of
TDM LSPs. This is an important operational requirement for operators. For
instance, when two IP routers are interconnected through an SDH/SONET
circuit this allows to dynamically change the bandwidth of that circuit
without releasing and re-establishing the circuit. Bandwidth modification is
inherent in MPLS and GMPLS. In the TDM cases, it requires some explanations
are a very few extensions.

Kind regards,

Eric

Eric Mannie
Network Engineering Strategy Senior Manager
EBONE

Terhulpsesteenweg 6A
1560 Hoeilaart - Belgium

Tel:    +32 2 658 56 52
Mobile: +32 496 58 56 52
Fax:    +32 2 658 30 06
E-mail: eric.mannie@ebone.com