Subject: [Pce] some question about draft-lee-pce-wson-signal-compatibility-00.txt :)

From: [email-masked]
Date: Tue, 8 Dec 2009 10:42:06 +0800

Hi Dr.Lee and Dr. Bernstein,

you  specifiy two flags in the Modulation Type List sub-TLV, that is S and 
I, in draft-lee-pce-wson-signal-compatibility-00.txt, see section 3.1.2.

When PCC requests a path, according to the "I" flag, there are two 
scenarios:
 I=1, indicates that PCC requests a path for the input signal, 
 I=0, indicates that PCC requests a path for the output signal

 See the picture below.

                            +-+-+-+
               Input signal + PCC + Output signal 
                            +-+-+-+
 
I think there is a little different from OSPF-TE flooding, which needs to 
flood the input and output 
modulation type. But for the PCE architecture, PCC should not request a 
path for the output signal. So maybe you can clarify this in the document.
 
Another question, PCE returns the Regeneration Point TLV to PCC, see 
section 3.2.3, why? 
I think the PCC just needs to know every hop's input and output 
parameters, and that is enough.
It should not care whether or not the LSP passes through a regeneration 
point.

The last one,  GPID Type Sub-TLV should be a general requirement in PCEP, 
not just limited to WSON compatibility, right?

B.R.

:)

Fei