[SR-Users] tcp hangup
andrei at iptel.org
Tue Apr 5 15:16:02 CEST 2011
On Apr 05, 2011 at 16:10, Juha Heinanen <jh at tutpro.com> wrote:
> i turned out that the problem below was caused by a firewall that
> blocked tcp session if it had been idle for a few minutes. the problem
> went away when i reduced tcp_connection_lifetime from 3610 to 120 sec.
> i don't know if it possible to configure tcp_connection_lifetime on per
> connection basis. for example, tcp connection to UA could have
> tcp_connection_lifetime=3610, since tcp session is kept active by UA
> sending crlfs, whereas tcp connection to another proxy could have a
> shorter tcp_connection_lifetime.
No, it's not possible to set it on a per connection basis.
It could be done (at the price of an extra int per tcp connection), but
the bigger problem is how to distinguish between proxy and UA
> -- juha
> > > i did some more debugging and wireshark shows that the 3.0 sr does not
> > > even try to send anything to the 3.1 sr over the tcp connection although
> > > netstat now tells at both hosts that the connection is established.
> > > instead sr 3.0 replies immediately after receiving invite from ua:
> > >
> > > SIP/2.0 477 Unfortunately error on sending to next hop occurred (477/TM)
> > >
> > > there is no related messages in syslog. perhaps tcp stack on 3.0 host
> > > has not got acks for earlier packets and just waits there.
> > The most likely candidates are:
> > - blacklisted destination (due to some previous error).
> > You could check it with sercmd dst_blacklist.view or
> > dst_blacklist.debug.
> > - some local firewall rules on the OUTPUT chain
> > running out of memory (but it's strange that you don't get any log
> > messages)
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