SIP in higher education

[Steve Blair <>]

Nimal Ratnayake wrote:

> Steve,
>
> It turns out that the problem was that I had not added "application 
> session" on
> the corresponding POTS dial peer.  After adding that everything works 
> fine.
>   

I can appreciate why that command caused problems. Maybe we should
put that comand in the cookbok. I'm glag the problem was resolved.

-Steve

> Thanks.
>
> Nimal R.
>
> Nimal Ratnayake wrote:
>
> > Apologies for duplicates. previously posted on 
> > .
> >
> > ---------
> >
> > Hi,
> >
> > When a call between a SIP phone and a PBX extension is transfered
> > by the SIP phone to another SIP phone, the SIP gateway does not
> > seem to handle the REFER correctly.  I am using a Cisco 3640 router
> > running IOS 12.3(12).  The call flow is as shown below ( I have
> > omitted the proxy in this picture)
> >
> >
> > SIP                             PBX-GW
> > IP=A.B.C.D                      IP=P.Q.R.S
> > 1602                            3423
> >
> > -------------INVITE--------------->
> > <------------TRYING----------------
> > <------SESSION PROGRESS------------
> > <--------------OK------------------
> > --------------ACK----------------->
> > ----INVITE c=IN IP4 0.0.0.0------->
> > <-----OK c=IN IP4 P.Q.R.S----------
> > --------------ACK----------------->
> > -------REFER Refer-To: 1600------->
> > <-----------Accepted---------------
> > <------------NOTIFY OK-------------
> > -------------- OK----------------->
> >
> >
> > Shouldn't the gateway do an invite to 1600 after receiving REFER
> > *before* sending NOTIFY?
> >
> > Any help or pointers to solve the problem would be appreciated.
> >
> > Thanks.
> >
> > Nimal Ratnayake