Hi All.

I've got a question about handling REFER messages. Below is a REFER message that my Grandstream GXP2000 phone generated when I transferred a call to another SIP phone on the same SER proxy.

The problem is that SER did a lookup('location') and couldn't find the phone number in the subscriber table, so it routed the message to the PSTN gateway.

SER should have looked at the Refer-To header to get the actual destination of the message.

How can I get SER to handle this message correctly? Should REFER messages hit the lookup('location') function in my ser.cfg script?

NOTE: my SER proxy sits behind a Cisco 3600 so the ALG functionality has altered the IP. The message shows my SER server as IP address 10.3.0.221

Regards,
Paul

U 2005/06/01 14:22:24.073518 66.90.46.29:5060 -> 10.3.0.221:5060
REFER sip:4075552279@66.243.109.99:5060 SIP/2.0.
Via: SIP/2.0/UDP 172.31.130.139;branch=z9hG4bK09ff837994d9e898.
Route: <sip:4075552279@10.3.0.221:5060;nat=yes;ftag=204ed7cd9666ebba;lr>.
Route: <sip:216.229.127.60:5060;lr>.
From: 3212514238 <sip:3212514238@66.243.109.99:5060>;tag=204ed7cd9666ebba.
To: sip:4075552279@66.236.245.100;tag=EB25EC-B85.
Contact: <sip:3212514238@172.31.130.139>.
Supported: replaces.
Refer-To: <sip:3212814820@sip.mycompany.com>.
Referred-By: <sip:3212514238@172.31.130.139>.
Call-ID: 13195134-3326638548-685571@66.243.109.99.
CSeq: 51906 REFER.
User-Agent: Grandstream GXP2000 1.0.1.8.
Max-Forwards: 70.
Allow: INVITE,ACK,CANCEL,BYE,NOTIFY,REFER,OPTIONS,INFO,SUBSCRIBE,UPDATE,PRACK.
Content-Length: 0.