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

[Iñaki Baz Castillo]

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?
NOTE: I know that I can add custom/propietary ";received" param in
Path URI and set in the registrar server:

  modparam("registrar", "path_use_received", 1)

but honestly that should be non needed.


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.


Regards.



-- 
Iñaki Baz Castillo
<ibc at aliax.net>