### Description
On our setup with Kamailio 5.2.1 with users connected via TLS. i see frequently TCP/TLS sessions remain in CLOSE_WAIT:
netstat -ntp |grep CLOSE tcp 238 0 172.17.217.10:5061 xxx.xxx.xxx.218:52613 CLOSE_WAIT 117912/kamailio tcp 4681 0 172.17.217.10:5061 xxx.xxx.xxx.125:8892 CLOSE_WAIT 117912/kamailio
In tcpdump i see, that the client send a TCP FIN,ACK and and the OS which is hosting the Kamailio send TCP ACK. But Kamailio is not closing. So the session remain in CLOSE_WAIT for a long time (over a hour)
We also have configured:
tcp_connection_lifetime=65 modparam("tls", "connection_timeout", 63)
Which should finally close after 65 second. But no effect.
### Troubleshooting
#### Reproduction
Register SIP clients via TLS, and then let the client close the TCP session ia TCP FIN,ACK
* **Operating System**:
Debian GNU/Linux 9