Please download the SDL file(s) and upload it/them to the post as that is much simpler to read and process than if you put the text into the post directly.
As you marked your answer as the solution to your question can we assume that you have managed to figure out your issue?
Please share screenshots of the setup of your SIP trunks on both CMs. In the SDL you get this.
SIP/2.0 503 Service Unavailable
Date: Fri, 03 Mar 2023 09:42:31 GMT
Warning: 399 "Unable to find a device handler for the request received on port 5060 from 10.183.0.244"
From: <sip:10.183.0.244>;tag=1989598117
Content-Length: 0
To: <sip:10.183.0.11>;tag=1651000644
Call-ID: b66be300-10001-131604-da8d090@10.183.0.244
Via: SIP/2.0/TCP 10.183.0.244:5060;branch=z9hG4bK145db24190c892
CSeq: 101 OPTIONS
SIP/2.0 503 Service Unavailable
Via: SIP/2.0/TCP 10.183.0.244:5060;branch=z9hG4bK145db52871e266
From: <sip:10.183.0.244>;tag=162290171
To: <sip:10.113.98.10>;tag=301477482
Date: Fri, 03 Mar 2023 09:44:18 GMT
Call-ID: b966d380-10001-131607-da90ae0@10.183.0.244
CSeq: 101 OPTIONS
Warning: 399 HMD-CUCM-PUB01 "Unable to find a device handler for the request received on port 42731 from 10.183.0.244"
Content-Length: 0
That would indicate what me and @b.winter has been stating from the start. You do not likely have the proper configuration in-place on your SIP trunks as the CM is rejecting the traffic coming from this and other IPs.
I also suspect that you might have a call loop situation, although this is not related to your issue that you asked about, as we see this in the shared logs.
SIP/2.0 483 Too Many Hops
Via: SIP/2.0/TCP 10.183.0.244:5060;received=10.183.0.244;branch=z9hG4bK145db84dbcfcbf
Call-ID: caafe000-10001-13160a-f695bb70@10.183.0.244
From: <sip:10.183.0.244>;tag=397146945
To: <sip:DLCC-IMP-PUB01.domain.local>
CSeq: 101 OPTIONS
Content-Length: 0
Sorry but I don’t understand what you’re trying to say in your last response. Would you mind to please clarify and try to write a properly worded sentence?
Why are you masking the IP address information? Isn’t that internal used private IPs?
Again if you want help please provide the asked for information, not something completely different. There is a reason, believe it or not, why we ask for specific information. It’s not done on a whim or randomly asking for information.
Your issue is caused by that you have something configured wrongly on your SIP trunk. This is making the far end CM rejecting the inbound traffic. That’s why the SIP trunk shows as down, with the cause of 503 Unavailable. If you do share the information asked for and reveal all the IP address of your CMs that process calls I’m pretty optimistic that we can get this to work for you. But if you persist in not being willing to do so we cannot do much.
Look at this and as well the post linked in it as it should match your situation. https://community.cisco.com/t5/ip-telephony-and-phones/sip-503-service-unavailable-unable-to-find-a-device-handler-for/td-p/3341493
