[SR-Users] Kamailio not processing SIP TCP

JR Richardson jmr.richardson at gmail.com
Tue Jan 17 16:37:47 CET 2017


> On Mon, Jan 16, 2017 at 10:29:39AM -0600, JR Richardson wrote:
>> Yes, I'm familiar with the methods sipcapture uses, I don't use HEP,
>> using raw socket capture, I think this may be a sipcapture issue,
>> debuging kamailio shows normal startup and processing of UDP SIP
>> packets, but does not show any activity with TCP packets.
>
> I never used HOMER sofar but when I saw your first message my thoughts
> was that this can't work in a simple way since for TCP you need to
> complete a 4 way handshake before you can start to send data.
>

Interesting. Are you referring to handshaking on the network stack or
SIP TCP TLS handshaking? I guess I can see it two ways.

1) if your talking about TCP/IP handshake, even though the SIP packet
comes into the mirror port on the host node, the kernel processing the
TCP packet is not establishing a valid connection due to no TCP
handshake because its only a monitor port, no transmit back, then the
kernel network stack does not pass the SIP TCP packet to the kamailio
process for capture because it drops the packet due to no valid
handshake?

2) the kernel network stack is passing the SIP TCP packet to the
kamailio process, but since kamailio cannot handshake back it drops
the packet and does not process through the sipcapture module. This
kinda breaks the whole capture ability for homer with SIP TCP. Using
ngrep, I see all SIP TCP packets, invite -->, trying <--, session
progress <--, request timeout <--, ack -->, etc...

So how would I diagnose if the network stack is the culprit? Debugging
kamailio is pretty straight forward, setup and listening for SIP TCP,
but never see any processing of any TCP packets.

Thanks.

JR
-- 
JR Richardson
Engineering for the Masses
Chasing the Azeotrope



More information about the sr-users mailing list