Served by PowerDNS - https://www.powerdns.com/
Resolver ID: powerdnsserver

HTTP/1.0 503 Service Unavailable
Cache-Control: no-cache
Connection: close
Content-Type: text/html

HTTP/1.1 501 method 'GET' not available
Cache-Control: max-age=0
Connection: close
Date: Wed, 26 Mar 2025 07:39:40 GMT
Pragma: no-cache
Server: pve-api-daemon/3.0
Expires: Wed, 26 Mar 2025 07:39:40 GMT

FPBX-15.0.17.43(16.13.0)

SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP nm;rport=63384;received=10.0.0.1;branch=foo
Call-ID: 50000
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=foo
CSeq: 42 OPTIONS
WWW-Authenticate: Digest realm="asterisk",nonce="1743409452/15674290b5402a0c3f4a93e78f70160d",opaque="6a5890066e7de2e1",algorithm=md5,qop="auth"
Server: FPBX-15.0.17.43(16.13.0)
Content-Length:  0

HTTP/1.0 503 Service Unavailable
Cache-Control: no-cache
Connection: close
Content-Type: text/html