Hi,

I'm receiving 478 status for a REGISTER sent to SER Proxy. I'm sending Register request URI in the form of domain name. But 478 status code as given by SER is an invalid response as per RFC 3261.
     When does SER responds with status code 478?
(Below is SIP register request packet and response packet)
Is it configuration problem or any thing wrong in my packet?
Register Request to SER:-->
    Request-Line: REGISTER sip:ser.testlab.com:5060 SIP/2.0
        Method: REGISTER
        Resent Packet: False
    Message Header
        Via: SIP/2.0/UDP 192.168.3.180:5060
        From: <sip:1801@ser.testlab.com:5060>;tag=425215125
            SIP from address: sip:1801@ser.testlab.com:5060
            SIP tag: 425215125
        To: <sip:1801@ser.testlab.com:5060>
            SIP to address: sip:1801@ser.testlab.com:5060
        Call-ID: 1002330992425@ser.testlab.com
        CSeq: 1 REGISTER
        Contact: <sip:1801@192.168.3.180:5060>;expires=60
        max-forwards: 70
        Content-Length: 0

Response from SER: <--
    Status-Line: SIP/2.0 478 Unresolveable destination (478/TM)
        Status-Code: 478
        Resent Packet: False
    Message Header
        Via: SIP/2.0/UDP 192.168.3.180:5060
        From: <sip:1801@ser.testlab.com:5060>;tag=425215125
            SIP from address: sip:1801@ser.testlab.com:5060
            SIP tag: 425215125
        To:
<sip:1801@ser.testlab.com:5060>;tag=a6a1c5f60faecf035a1ae5b6e96e979a-d8b4
            SIP to address: sip:1801@ser.testlab.com:5060
            SIP tag: a6a1c5f60faecf035a1ae5b6e96e979a-d8b4
        Call-ID: 1002330992425@ser.testlab.com
        CSeq: 1 REGISTER
        Server: Sip EXpress router (0.8.14 (i386/linux))
        Content-Length: 0
        Warning: 392 192.168.3.198:5060 "Noisy feedback tells:  pid=2361
req_src_ip=192.168.3.180 req_src_port=5060
in_uri=sip:ser.testlab.com:5060 out_uri=sip:ser.testlab.com:5060 via_cnt==1"
Thanks and regards,
 
naresh