[sr-dev] Path support and UDP "ping" like \x00\x00\x00\x00 to Contact/received URI?

[Henning Westerholt]

On Wednesday 31 August 2011, Iñaki Baz Castillo wrote:
> Hi, using Kamailio 3.2.0-dev5 (x86_64/linux) 552425.
> 
> Related conf:
> ------------------------------
> modparam("registrar", "use_path", 1)
> modparam("registrar", "path_mode", 1)
> 
> modparam("nathelper", "natping_interval", 10)
> modparam("nathelper", "sipping_method", "OPTIONS")
> # No flag is set for NAT pinging...
> ------------------------------
> 
> REGISTER arrives coming from an outbound proxy which added Path header:
> ------------------
> REGISTER sip:REGISTRAR SIP/2.0
> Path: <sip:PROXY;transport=udp;lr>
> Contact: <sip:pepe at 192.168.1.232:23652;transport=udp>;expires=3600
> -----------------
> 
> Registration is performed, and since that, Kamailio starts sending
> ugly UDP datagrams to the Contact URI of the REGISTER:
> 
> U 2011/08/31 13:32:21.558022 REGISTRAR -> 192.168.1.232:45329
> \x00\x00\x00\x00
> 
> So first question is: why is the UDP "ping" sent to the REGISTER
> Contact URI instead of sending it to the Path URI?

Hi Iñaki,

well, why is this UDP ping sended at all? Do you've anything in the logfiles 
about a timer that is run, ping sending etc..

> Second question. Wouldn't be better if the UDP "ping" contains
> CRLF+CRLF rather than \x00\x00\x00\x00 ? At least, CRLF+CRLF is
> already defined as a SIP TCP ping.

Sounds indeed better.

Best regards,

Henning