[Kamailio-Users] Extra byte in Content-length header

[Iñaki Baz Castillo]

El Martes, 9 de Febrero de 2010, Vikram Ragukumar escribió:
> Could it be that this byte was appended somewhere downstream(possibly at 
> the wireless router..) or can i be sure that the byte was added during 
> SIP Message construction by the cellphone software ?

You cannot know it by just inspecting the request.
You could be behind a fu***** SIP-ALG enabled router rewritting SIP requests 
"to fix the NAT".

You can get more information here:
   http://www.voip-info.org/wiki/view/Routers+SIP+ALG

To detect if you router has SIP-ALG enabled you can try various options:

1) Ensure you are not using STUN in your client so the request arriving to the 
proxy should contain client private address in Via and Contact header.

2) Try an utility I coded which detects if a host is behind a SIP-ALG enabled 
router:
  http://dev.sipdoc.net/wiki/sip-stuff/SIP-ALG-Detector

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