If your PBX hosting environment or PBX itself are protected by a firewall, ensure that your network firewall allows traffic from the IP Addresses listed below.
Signaling Traffic:
UDP Ports 5060 – 5065 must be opened to support SIP signaling. 5060 is the default port for UniTel-SIP
199.180.220.89
199.180.220.91
208.89.104.3
Media RTP proxies:
Allow *ALL* UDP traffic to/from Media IPs below:
199.180.223.109
45.55.33.77
157.230.238.197
45.33.70.196
45.33.71.83
159.65.107.252
45.33.14.21
159.89.122.218
167.71.237.189
172.104.226.108
139.162.250.71