SDH/SONET concatenation signal types

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

I have a question on the different SDH/SONET concatenation signal types proposed in draft-lin-ccamp-ipo-common-label-request (e.g. VC-n-Xv, VC-n-Xv LCAS, VC-n-X). Defining different signal types makes only sense if a different behaviour is assumed. What is the difference between these types? Is my interpretation correct?

VC-n-Xv: fixed virtual concatenation; co-routed
VC-n-Xv LCAS: flexible virtual concatenation; different routes
VC-n-X: no concatenation; co-routed

For the later as it could be also used for all other signal types would it be better to introduce some kind of grouping for signal types that have to be co-routed?
For all the 3 types how would you indication the timeslot, position of the individual VCs as the may/will not use contiguous slots. If different routes are used they even go accross via different interfaces and NEs and you cannot include  them in a single label request.

Regards

Juergen