SIP in higher education

[Nimal Ratnayake <>]

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.

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