[Serdev] IPv6 to PSTN setup

[Lambros Lambrinos]

Hi,
I've been playing with the following setup:

ipv6 ua --- ser (v6) --- msp gateway --- ser (v4) --- cisco 3640 pstn gateway
						  --- cisco ip-phone

Everything works fine with the IP phone but routing the call
to the PSTN gateway causes it to return a 400 Malformed/Missing Request
in response to the packet forwarded to it from the ser(v4)

If i use the ip-phone to make a call via the pstn gateway
(i.e. involving only the V4 SER) everything is fine.
This makes me believe that the most likely cause of the crash
is that the PSTN gateway can not understand the IPv6 address
in the Via: or Record_Route: header fields (see packets below).

It seems that a solution is to remove the entries
with the IPv6 addresses at some point before sending the packet to
the PSTN. Obviously, this information should be inserted back
before the reply is forwarded to the entity initiating the call.

Where do people think is the best place to do that ?
SER or the MSP gateway ?

Regards,
Lambros


PACKET SENT FROM SERv4 TO PSTN GATEWAY

Session Initiation Protocol
    Request-Line: INVITE sip:3007 at 128.16.67.2:5060 SIP/2.0
    Message Header
        Record-Route: <sip:3007 at 128.16.234.7;ftag=49F56B1E;lr=on>
        Max-Forwards: 9 
        Record-Route: <sip:[2001:630:13:101:2E0:18FF:FE3E:ECB2];ftag=49F56B1E;l
r
=on>
        Via: SIP/2.0/UDP 128.16.234.7;branch=z9hG4bK86ba.d7fafbd5.0
        Via: SIP/2.0/UDP 128.16.67.73:5062
        Via: SIP/2.0/UDP [2001:630:13:101:2e0:18ff:fe3e:ecb2];branch=0
        Via: SIP/2.0/UDP [2001:630:13:101:204:23ff:fe0b:dc58]
        CSeq: 6566 INVITE
        To: <sip:3007 at 128.16.234.7>
        Content-Type: application/sdp
	From: "Manish Lad" <sip:1006 at frostie.cs.ucl.ac.uk>;tag=49F56B1E
        Call-ID: 1658003513
        Subject: sip:1006 at frostie.cs.ucl.ac.uk
        Content-Length: 185
        User-Agent: KPhone/3.11
        Contact: "NAT Proxy" <sip:proxy at 128.16.67.73:5062;realuri=0-ralOcJk1sRA
M
6AlMTdrMoAvMTMvMTAmO6IlNDdnMrZbObZaMGIvZGMqODip-bFj-sBk-cQz9WRl>
Session Description Protocol
    Session Description, version (v): 0
    Owner/Creator, Session Id (o): username 0 0 IN IP4 128.16.67.73
    Session Name (s): The Funky Flow
    Connection Information (c): IN IP4 128.16.67.73
    Time Description, active time (t): 0 0
    Media Description, name and address (m): audio 32974 RTP/AVP 0 97 3
    Media Attribute (a): rtpmap:0 PCMU/8000
    Media Attribute (a): rtpmap:3 GSM/8000
    Media Attribute (a): rtpmap:97 iLBC/8000


THE RESPONSE FROM PSTN GATEWAY

Session Initiation Protocol
    Status-Line: SIP/2.0 400 Bad Request - 'Malformed/Missing Record Route'
    Message Header
        Via: SIP/2.0/UDP 128.16.234.7;branch=z9hG4bK86ba.d7fafbd5.0,SIP/2.0/UDP

128.16.67.73:5062,SIP/2.0/UDP [2001:630:13:101:2e0:18ff:fe3e:ecb2];branch=0,SIP
/
2.0/UDP [2001:630:13:101:204:23ff:fe0b:dc58]
        From: "Manish Lad" <sip:1006 at frostie.cs.ucl.ac.uk>;tag=49F56B1E
        To: <sip:3007 at 128.16.234.7>;tag=88098FAC-15AD
        Call-ID: 1658003513
        CSeq: 6566 INVITE
        Content-Length: 0