Router Settings for Keypad and SIP Phones
If you're using a SIP phone behind a firewall or router, you may need to open up ports for it to function properly. Most modern phones and modern routers can accomplish this for you automatically using UPnP or other smart port forwarding configuration. However, larger enterprise firewalls may not do this for you and require manual intervention.
5060 (UDP/TCP) and 5061 (TLS)
10,000 to 20,000 (UDP)
For the full, detailed information from Twilio, our VOIP backbone, please look here: