[Kamailio-Users] no free tcp receiver

Gawith gawith at gmx.de
Fri Dec 5 14:23:57 CET 2008

Klaus Darilion schrieb:
>> That's the point. The server does nearly nothing:
>> I have 10 TCP childs and only about 2 INVITEs/sec.
> Then there is probably something going wrong.
> I would:
> - stop the proxy and all clients
> - start tcpdump or wireshark (without capture filter)
> - start the clients (if you have clients)
> - make a single call, hang up
> - repeat the single call, hang up.
> Then analyze the capture file: Are there "strange" SYN packets trying to 
> establish a connection which does not work? Are there other TCP errors 
> (RST, FIN ...)
> I suspect that workers are trying to establish new tcp connection which 
> do trigger a timeout - and as TCP handling in Kamailio is blocking the 
> TCP workers are busy when new requests are received.

I've check the traces and can not see any suspicious SYNs etc. All looks 
But I recognized that the "no free tcp receiver" comes along with a 
"CRITICAL:core:handle_io: empty fd map" messages. Nevertheless, I have 
no clue at all...

Just for clarification: if I have 5 TCP children, then only 4 childs are 
worker processes. If a sip peering partner with 4 different SIP server 
has a network split, all my worker childs are blocked and wait for TCP 
timeouts. In the meantime, no calls to anywhere else is possible. Right?


More information about the Users mailing list