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. -- 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) _______________________________________________ SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
