T-Mobile Wifi Calling – ER081 Firewall Port Summary

Open the following ports on your firewall:

  • TCP 5060-5061
  • UDP 4500 (aka IKE Traversal)  –  Note: This is the port the call data goes through

Additionally, you may need to let IKE Key Exchange traffic through.

  • UDP 500

Other errors:

REG99 – Go to my.t-mobile.com and update your E911 address (even if you previously have)