[OpenSER-Devel] [Serdev] Possible bug in the tm module in the presence of packet loss/branches

[Dan Pascu]

On Wednesday 12 March 2008, Maxim Sobolev wrote:
> If you want to isolate ingress and egress dialog state and bill user
> only for what he has actually sees use b2bua. Then you will be able to
> end ingress call with 487 immediately upon receiving CANCEL and don't
> bill user for anything that happens on the other side after that,
> letting egress calls to complete independently and not affect what user
> sees in her bill.

I disagree. As I said it's not a matter of billing, it's a matter of 
making a connection where you do not want to. Even if your b2bua 
immediately ends your leg, it may still have the same issue on the 
outbound leg and connect to the service you refused to connect to. While 
the b2bua can chose not to emit a bill for that call because it knows the 
context, it cannot isolate you from the potential legal bindings that 
result from making a connection to that address. Rest assured that the 
other side will consider the original caller as connected to that service 
and that he has accepted all the terms and conditions since he has made 
the connection and will have no clue that a b2bua is in the path and some 
entity that cannot be made legally responsible (the b2bua) is connected 
instead.

In the end it resumes to the fact that the protocol allows for another 
entity in the network to have control over me canceling a call and that I 
have no control over my own device's behavior, which is a shortcoming in 
the protocol IMO.

-- 
Dan