Subject: [PWE3] Set up of TDMPWs after the establishment of a call

From: Javi Muñoz <[email-masked]>
Date: Tue, 13 Dec 2011 13:15:51 +0100

Recommendations [ITU-T Y.2262; Y.2012] proposes to support multichannel 
ISDN calls using TDMoIP (UDP/IP TDMPWs). However, they do not indicate 
what kind of TDMPW, or when it must be set up.

The scenario is:

|ISDN TE| [1xD channel ] --> |AGW|<-->  MGC (Q.931/SIP)<--> |AGW|<-- 
[1xD channel ] |ISDN TE|
|_______| [NxB channels] --> |___|<--------[TDMPW]--------> |___|<-- 
[NxB channels] |_______|

* AGW (Access Gateway) would also be the PE (Provider Edge) of the TDMPW.

I understand that:

* Static TDMPWs (SAToP, CESoPSN, TDMoIP AAL1) must be set up before 
calls: so, they are not a good choice in this case for reasons of 
scalability (It will require the establishment of a PW with every 
potential destination AGW, which may be in the numbers of tens of 
thousands for a single PNO).

* TDMPW TDMoIP AAL2: I think it is possible to set up the TDMPW between 
two AGWs when the first call occurs between them. For second and 
subsequent calls, it would expand the number of CIDs of the TDMPW. The 
TDMPW would be deleted when all calls between the two AGWs are released.

Two questions:

(a) Is it valid this proposed use of TDMPWs?

(b) Each AGW/PE could belong to a different PNO. Is it possible to 
establish a TDMPW between two PEs that belong to different PNO?

Regards,

Javi