Port 5061: SIP over TLS
Port 5061 is SIP over TLS, the encrypted version of VoIP call signalling.
What runs on port 5061
SIP over TLS protects call setup messages, including the details used to log a phone in, on TCP 5061. It is often paired with SRTP to encrypt the voice itself. Many business VoIP providers and Microsoft Teams Direct Routing use it.
On a home network
VoIP phones and adapters that support encryption connect out on 5061. Home devices rarely listen on it.
If port 5061 is reachable from the internet
Encryption stops eavesdropping on signalling but not password guessing, so an exposed phone system on 5061 still needs strong extension passwords and fraud limits. If you do not run your own phone system, nothing should answer on 5061.
How to check whether it is open on your network
If an outside scan shows 5061, trace the port forward to the phone system and confirm you meant to publish it.
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