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Command Line Interface

How to use VoipNow behind a firewall ​

This article provides guidelines on the ports and firewall rules that must be configured to ensure proper operation of a VoipNow server deployed behind a firewall.

Port(s)ProtocolDescriptionNotes
22TCPSSH remote access
25TCPSMTP for email2fax
53UDPDNS — required for outgoing DNS requests
443TCPWeb interface (HTTPS)
5060TCP/UDPKamailio SIP signaling
5061TCP/UDPKamailio SIP signaling over TLS
5050TCP/UDPAsterisk SIP signalingUsed for internal communication.
Public inbound can be blocked
3478TCP/UDPSTUN/TURN traffic required by ICE for NAT traversal
10000–20000UDPRTP audio/media traffic
4000–5999UDPT.38 fax signaling
11211TCPHubring, normally localhostUsed for internal communication.
Public inbound can be blocked.
Open remotely only in distributed environments
Last updated: Dec 11, 2025