From VoIP.ms Wiki
When configuring your firewall to work with VoIP.ms, there are certain ports which need to be enabled to avoid quality and/or stability issues. Generally these ports are configured by default; however for users requiring the specific port numbers and protocols please use the information below:
Port = 5060 *Port range = 5060 - 5080 Protocol = UDP or UDP/TCP Direction = Incoming and Outgoing
The RTP port may vary by device. If configuring a firewall you will want to configure a range which includes the default RTP port in your device.
Port range = 10001-20000 UD Protocol = UDP or UDP/TCP Direction = Incoming and Outgoing
- This is for users who may require a port range for their firewall or router
If you have a secured/restricted network and need to know the IP addresses to allow for VoIP.ms, then please use the addresses found Here .
If your router includes a SIP ALG and/or SPI Firewall setting please ensure that it is disabled.
When using a SonicWALL and a PBX behind that SonicWALL, some of the inbound SIP connections may get refused because the SonicWALL is quick to timeout the UDP sessions on the firewall. Please Click Here for further details.
If you still have questions on this topic please contact us for further assistance.