Skip to Content.
Sympa Menu - Re: [] Cisco gateway not handling REFER correctly?

Subject: SIP in higher education

List archive

Re: [] Cisco gateway not handling REFER correctly?

Chronological Thread 
  • From: Steve Blair <>
  • To: Jeremy George <>
  • Cc:
  • Subject: Re: [] Cisco gateway not handling REFER correctly?
  • Date: Thu, 24 Nov 2005 07:10:29 -0500


There have been several issues with REFER and call transfer. I was looking in Bug Tracker
to remind myself of the details. It seems that the problems I remember were in IOS 12.2
releases which we no longer run. However bug #CSCea86574 is a possible suspect, at
least for my current problem. In my current case the sip domain name in the Refer-To
header has been rewritten to be an SRV name instead of an IP address by the time
the REFER message gets back to the gateway.

The bug report suggests this issue has been fixed however I am not running any of the
IOS releases in which the bug has been reported to be corrected. I'll come back to this
on Monday when I return.

Blind and Consultative transfers have been working for us. This is the first time in about
eight months that we have experienced an issue. Today all of our phones are Cisco phones
however this hasn't always been the case. Call transfer was working in the previous
mixed vendor environment.


Jeremy George wrote:


Does it make a difference whether the IP devices are all Cisco or
not? I _seem_ to recall blind transfers work in all Cisco mode but
not necessarily otherwise.

- Jeremy

On Thu, 24 Nov 2005, Steve Blair wrote:

Date: Thu, 24 Nov 2005 06:49:12 -0500
From: Steve Blair


Subject: Re: [] Cisco gateway not handling REFER correctly?

Hello Nimal:

I'm out of the office for out holiday however when I return on Monday I
will look into this a bit. I think I am having a similar problem. For me a
call comes in from the PSTN via the Cisco gateway to an IP phone. The
IP phone blind transfers the call to another IP device and the call drops.
I'll let you know if I discover anything of interest. May I ask that you
do the same?


Nimal Ratnayake wrote:

Apologies for duplicates. previously posted on



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)

1602 3423

<------SESSION PROGRESS------------
----INVITE c=IN IP4>
<-----OK c=IN IP4 P.Q.R.S----------
-------REFER Refer-To: 1600------->
<------------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.


Nimal Ratnayake

Archive powered by MHonArc 2.6.16.

Top of Page