No incoming calls at random

Hi,

Running Asterisk Version: 1.4.21.2
PIAF: 1.2.5
FREEPBX: 2.5.1.0 (with all module updates)

When I do some test calls from outside to the asterisk, sometimes for 2 minutes the call doesn’t come thru, the line stays dead. The logs then only shows 1 line:
[Oct 30 14:55:45] WARNING[2795] rtp.c: Unable to set TOS to 184
…and that’s it.

Below what happens after a successfull call, followed by some failed test-calls.

[Oct 30 14:03:49] VERBOSE[2121] logger.c: == Spawn extension (app-announcement-10, s, 5) exited non-zero on ‘SIP/{ip-siptrunk-provider}-b75031d0’
[Oct 30 14:04:01] WARNING[21839] rtp.c: Unable to set TOS to 184
[Oct 30 14:04:39] WARNING[21839] rtp.c: Unable to set TOS to 184
[Oct 30 14:05:04] WARNING[21839] rtp.c: Unable to set TOS to 184
[Oct 30 14:05:29] WARNING[21839] rtp.c: Unable to set TOS to 184
[Oct 30 14:05:42] WARNING[21839] rtp.c: Unable to set TOS to 184

Below this after a successfull call and some failures followed by the first log line when it suddenly starts working again.

[Oct 30 14:55:37] VERBOSE[2904] logger.c: == Spawn extension (app-announcement-9, s, 5) exited non-zero on ‘SIP/{ip-siptrunk-provider}-0933bbb8’
[Oct 30 14:55:45] WARNING[2795] rtp.c: Unable to set TOS to 184
[Oct 30 14:56:05] WARNING[2795] rtp.c: Unable to set TOS to 184
[Oct 30 14:56:36] WARNING[2795] rtp.c: Unable to set TOS to 184
[Oct 30 14:57:01] WARNING[2795] rtp.c: Unable to set TOS to 184
[Oct 30 14:57:17] WARNING[2795] rtp.c: Unable to set TOS to 184
[Oct 30 14:57:32] WARNING[2795] rtp.c: Unable to set TOS to 184
[Oct 30 14:57:32] VERBOSE[2908] logger.c: – Executing [{myphonenumbergoeshere}" @from-sip-external:1] NoOp(“SIP/{ip-siptrunk-provider}-0935f150”, “Received incoming SIP connection from unknown peer to {myphonenumbergoeshere}”) in new stack

If anyone has any suggestions on this scary behaviour, please respond.