SIP and the Internet

Generic SIP ports

  • Port 5060 (UDP or TCP) for SIP
  • Port 5061 (TCP) for TLS communications –if using secure SIP
  • Port 4000-32767 (UDP) (send & receive) for RTP/RTCP communications (2 ports per call)

LQ 4.0 will only use ports 4000 - 4015 locally but will still be able to connect to any other RTP/RTCP ports.

Secure SIP and TCP is not supported in LQ 4.0

Network Address Translation (NAT) and Firewall

NAT and many firewalls “hide” private networks behind a public IP address. This normally means that SIP calls can be initiated from a private network to the Internet but not the other way around. Also, firewalls commonly deny access to port numbers associated with Voice Over IP (VoIP) applications.

This aspect of SIP can be handled by technologies designed to traverse firewalls such as STUN, TURN and ICE. Some VoIP service providers use proprietary server side solutions that do not require STUN/TURN/ICE servers.

Using SIP with LQ

When using SIP with LQ Series units, you need an IP - Private Branch Exchange (IP - PBX) to act as a SIP server. This PBX can be a physical unit, or you can use a cloud-based IP-PBX service.

Note: LQ SIP does not currently work with STUN/TURN/ICE.

More information on firewall/NAT: