thoughts on draft-vasseur-ccamp-inter-area-as-te-00.txt

[Dimitri Papadimitriou <dpapadimitriou@psg.com>]

hi arthi, jp, all,

reading draft-vasseur-ccamp-inter-area-as-te-00.txt
the following came into my mind, why is there a need
to signal the "signaling method": contiguous versus
stitching vs nesting ? 

the reason provided in the document about "control" 
is unclear, is the sensitivity of the carried traffic
dependent of the signaling method ? 

"For the sake of illustration, a Head-end LSR, may 
desire to prevent stitching or nesting for a traffic 
sensitive inter-area/AS TE LSPs that require a path 
control on the head-end LSR."  

it seems for me that "signaling the signaling method" 
introduces here in addition to the protocol issue(s),  
policy issues:

"Ox01: Contiguous LSP [...]

When set, this indicates that a boundary LSR MUST 
not perform any stitching or nesting on the TE LSP 
and the TE LSP MUST be routed as any other TE LSP 
(it must be contiguous end to end). [...]

A mid-point LSR not supporting contiguous TE LSP 
MUST send a Path Error message upstream with error 
sub-code=17 Contiguous LSP type not supported."

thanks,
- dimitri.