SIP/2.0 200 OK
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=360460-0-13c4-9017b-377b57e9-9017b
Call-ID: 50000
CSeq: 42 OPTIONS
Via: SIP/2.0/UDP nm;received=224.98.24.192;rport=26810;branch=foo
Supported: 100rel,replaces,timer,path
Contact: <sip:127.0.0.1:5060>
Content-Length: 0

nginx

HTTP/1.1 502 Bad Gateway
Server: nginx
Date: Sun, 02 Feb 2025 02:36:20 GMT
Content-Type: text/html
Content-Length: 552
Connection: keep-alive
Keep-Alive: timeout=20