[SR-Users] handle_tcpconn_ev(): connect failed

[Daniel Tryba]

On Thu, Sep 07, 2017 at 11:03:49AM +0300, Donat Zenichev wrote:
[snip]
> ERROR: <core> [tcp_main.c:4070]: handle_tcpconn_ev(): connect
> XXX.XXX.XXX.XXX:52185 failed
> 
> The port that kamailio2 tries to use to relay the ACK, is port that
> endpoint used to establish the dialog with kamailio1 and actually his TCP
> connection is now established with kamailio1.
> So kamailio2 tries to use the same port and gets the error.
> 
> And this is proper behavior I think.
> 
> There is no problem with UDP transport.

This problem also exists with UDP when NAT is involved. I don't think
there is anything you could do to solve this problem with TCP/TLS
connections, especially with NAT. 

Having a similar setup with failover for the loadbalancers, I take for
granted that TCP/TLS will fail in case of a failover (but UDP will keep
working after failover due to the stateless nature of it). Luckily
kamailio is rock solid and the only reason the TCP sockets fail is a
restart of kamailio on config change.