[BLISS] Issue with CC possible indication and forking proxies

Hi,

There is an issue with the transport of the CC possible indication in
the 486 response and the forking proxies. 

The issue is following - consider an INVITE from A to AOR-B that gets
forked by a proxy to AOR-C and AOR-D. If any of the targets AOR-C and
AOR-D is busy the possible CCBS possible indication in any of the 486
responses will not survive the response aggregation in proxy and will
not make it's way to the A. Let's call this scenario A) proxy with no
monitor forking to foreign AORs.

In my opinion there is no issues, as there is no possible way to make
such a scenario function fair, so there is not problem is the CC service
will not function in this case at all.

In the following scenarios the assumption is that there are no proxies
from the scenario A) preceding the acting proxy. If there are any than
the scenario A) applies.

Consider an INVITE from A to AOR-B that gets forked by the proxy with
monitor to the Contact-B and AOR-C. If the Contact-B is busy and AOR-C
is ringing, the 486 and 180 responses get aggregated to 180 with no
CCNR. If both Contact-B and AOR-C are busy the proxy with the monitor
will provide the 486 with CCBS possible indication monitoring the status
of the Contact-B. If Contact-B is ringing than independent from the
state of the AOR-C the proxy with the monitor will provide the 180 with
the CCNR possible indication. 
Let's call this scenario B) proxy with monitor forking to local contacts
and foreign AORs

Scenario C) would be proxy with monitor forking to local contacts only.
This is where the local policy for the aggregation and generation of the
CC possible indication would apply.

To sum-up - the scenario B and C will function properly, the scenario A
will not function, but this is acceptable from my point of view as the
A) scenario is not the common case. 

This all means that we do not have to do anything special to support the
transport of 486 or 180 messages carrying the CC possible indication
from B to A.

Comments, questions?

Greetings,
Denis