Subject: [cuss] REQ-4 comment

From: "DRAGE, Keith (Keith)" <[email-masked]>
Date: Fri, 1 Oct 2010 23:55:39 +0200

Requirement 4 states:

   REQ-4: The mechanism will allow UUI to be able to survive proxy
   retargeting.

      Retargeting is a common method of call routing in SIP, and must
      not result in the loss of user to user information.

I would like to extend this to be:

   REQ-4: The mechanism will allow UUI to be able to survive proxy
   retargeting or any other form of redirection of the request.

The reason for this is that in the ISDN, the UUI survives call forwarding, and I would like any SIP service simulating the ISDN call forwarding service to be able to do likewise.

Specifically if A forwards to B1, B1 forwards to B2, and B2 forwards to C, B1 and B2 will both receive the UUI if they receive the information about the forwarded call. Further C will also receive the UUI.

As the call forwarding may not be performed by a proxy, it seems to be sensible to make this requirement a little wider.

regards

Keith