RE: SDH/SONET in GMPLS

[James Scott <jscott@calient.net>]

hi manoj,

mj> As per SONET standard, each STS-1 SPE 
mj> is divided into 7 VT-groups. Each VT 
mj> group may contain 4 VT1.5, 3 VT-2s, 
mj> 2 VT-3s or 1 VT-6.  Furthermore, each 
mj> VT-group shall contain one size of VT. 
mj> however, each VT-group within STS-1 may 
mj> be of different VT-size. Does this type 
mj> of statement holds true for SDH also ? 

yes.  i don't recall that SDH spells out the
rules on trib mixing explicitly as SONET does.
however, the intent of the rules should be
applicable to either protocol.  that being,
to eliminate the possibility of inefficient
usage of the columns within the trib group
due to mismatched trib types being applied.

mj> Is GMPLS supports this or it has some 
mj> restrictions for these configurations?

draft-ietf-ccamp-gmpls-sonet-sdh-02.txt
defines labels with VT/TU granularity as
well as mappings/encodings for both
contiguous and arbitrary concatenation.
this should supply vendors with an adequate
supply of rope.

hope this helps.

cheers,

james