SIP stands for "Session Initiation Protocol," and refers to a signaling protocol that can run over TCP or UDP and is commonly used for voice and video communications. SIP servers are often the connection points for VOIP calls.
NodePing's SIP monitoring can verify that your SIP server is responding to new requests. The check does not initiate a call, but rather tests that the the server accepts a SIP connection by sending the OPTIONS command and watching for the response. Even if your server does not support the OPTIONS command and returns an error, this indicates that the server is up and operating, so the check succeeds.
To set up SIP server monitoring,
If you're running your SIP service on a port other than the default 5060, you can specify the port in colon notation such as 'sip.nodeping.com:6550'