Hi, I'm currently working on a new module, that allows setting the TCP keepalive options by socket, on demand, through the kamailio cfg: https://github.com/kamailio/kamailio/tree/coudot/tcp_keepalive/modules/tcp_… This allows turning this mechanism on only when needed during the whole lifetime of a SIP/TCP connection. In our case, this would be only during a media session, to efficiently detect a disconnection (clients are smartphones on mobile network). Then, disabling keepalive when the session ends allows to save on network traffic, and battery for the client. Setting the options on the socket is straightforward when the TCP worker owns the file descriptor, but it's more tricky when it does not. In the latter case, I've been re-using the core functions from pass_fd.c. Are the functions from pass_fd safe to use from modules? Apart from close()ing the fd after setting the sock options, is there anything to take care of in term of resource locking or releasing? Any feedback is appreciated. Cheers,