RE: last call comment on draft-ietf-ccamp-gmpls-sonet-sdh-00.txt

[Heiles Juergen <Juergen.Heiles@icn.siemens.de>]

Alan,

hierachical LSP setup in Sonet/SDH and other transport planes is an issue currently not addressed by GMPLS. The Sonet/SDH naming tree (TDM-LSR link lable) for example doesn't fit with independent higher and lower order VC setup. For example the route of a VC-4 may change (use different STM-N ports at the equipment) while the endpoints are still the same. The VC-12 transported via these VC-4 don't have to care about the STM-N port only about the VC-4 endpoints. The current definition requires the port and full multiplex structure. AS not much thoughts are spent on the issue the current definition might not work with future extensions that support hierachical structures.

Regards

Juergen 

> -----Original Message-----
> From:	Kullberg, Alan [SMTP:akullber@netplane.com]
> Sent:	Thursday, May 24, 2001 5:44 PM
> To:	'Mannie, Eric'; 'Kireeti Kompella'
> Cc:	'ccamp@ops.ietf.org'; 'mpls@UU.NET'
> Subject:	last call comment on draft-ietf-ccamp-gmpls-sonet-sdh-00.txt
> 
> The following paragraph is from section 3 of
> draft-ietf-ccamp-gmpls-sonet-sdh-00.txt.
> 
>   When hierarchical SDH/SONET LSPs are used, an LSP with a given
>    bandwidth can be used to tunnel lower order LSPs.  The higher
>    order SDH/SONET LSP behaves as a virtual link with a given
>    bandwidth (e.g. VC-3), it may also be used as a Forwarding
>    Adjacency. A lower order SDH/SONET LSP can be established through
>    that higher order LSP. Since a label is local to a (virtual) link,
>    the highest part of that label is non-significant and is set to
>    zero.
> 
> The LSP Hierarchy draft introduces Link Mux Capability.  There is a value
> defined for TDM Switch Capable.  In order to support the hierarchy in the
> above paragraph, TDM Switch Capable would need to be split into multiple
> values, one for each level of the SDH/SONET multiplexing structure.
> 
> What do you think?
> 
> Alan
>