SIP Trunk keeps disconnecting

Hi all,
my SIP trunk provider is T-Mobile PL. I configured the trunk in FreePBX 15.0.21 with Asterrisk version: 16.19.0 and it works, but I’m facing 2 problems.
First problem is, that the trunk disconnects after a random time. Sometimes it is after 2 days, sometimes it works for a whole month before it gets offline. When it happens, many SIP REGISTERs are being sent to the provider without any respose. To fix it, I have to login into FreePBX, disable the trunk, wait 15 minutes and turn it back on.
Second problem is related to incomming calls. About 50% of incoming calls are unsuccessful (voice annoucement “the subscriber is temporarily unavailable”). I don’t see any INVITE coming into FreePBX in that case. All outgoing calls work properly.
Now some info regaring my provider. The auth username is like [email protected], but they use a proxy (, through which all communication happen. I configured it as;lr
Their recommendation say thay the SIP registration expiry time should be 3600s so I configured like that. The provider also sends SIP OPTIONS packet every 60s, on FreePBX side qualify frequency is also set to 60s.
When I configured this trunk on an Ericsson-LG IP8820 phone, it worked without any problem for a few months on the same internet connection.
Do you guys have any ideas what can be done to fix these 2 problems?

You need to give us more information. Please show your configuration and SIP traces.

Here is my configuration:

Cap file containing sip trace with 2 weeks of signalling captured:

What does the provider logs say about it?

Make sure that ( is the only source for incoming calls. This kind of issue can happen if the provider uses 2 distinct proxies with load sharing. Not sure about FreePBX but I got the same with Avaya.
Check if the incoming UDP INVITE packet is just not accepted by Asterisk at your side or it does not reach it at all.

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