Moved to ID 3 months ago, previously with Vodafone. I can wifi call on all wifi except one of my work wifis where I need to make calls. Previously connected with the same phone but Vodafone Network to the WiFi and could wifi call, so not a phone issue.
Have tried:
Resetting phone
Resetting network settings
New ESIM
IT have tried (on the WiFi side)
Disabled SIP ALG
Ensured Ports for UDP Traffic are open and not blocked, and checked with an Nmap Scan.
Enabled Fast Roaming and revoked Sticky sessions to ensure you are always on the best possible connection
Ensured all settings match sister sites configuration
Any help would be appreciated!
Best answer by WelshPaul
Vodafone’s implementation of Wi-Fi calling won't be the same as THREE’s as there is no set standard in use across all networks. They can all use different ports and protocols.
Three UK Wi-Fi calling typically requires specific firewall ports to be open for IPSec VPN connectivity, which is used to tunnel voice traffic. The essential ports are UDP 500 (IKE), UDP 4500 (NAT-Traversal), and often IP Protocol 50 (ESP). Ensuring these, along with proper SIP signaling (UDP/TCP 5060), are open on restricted networks enables the service.
UDP 500: Used for IKE (Internet Key Exchange) to establish the secure VPN tunnel.
UDP 4500: Used for NAT-Traversal (NAT-T) to allow IPSec traffic through home/public routers.
IP Protocol 50 (ESP): Encapsulating Security Payload, crucial for encrypting the data.
If calls still fail, check for firewall restrictions on UDP traffic and ensure your router allows IPSec pass-through.
Vodafone’s implementation of Wi-Fi calling won't be the same as THREE’s as there is no set standard in use across all networks. They can all use different ports and protocols.
Three UK Wi-Fi calling typically requires specific firewall ports to be open for IPSec VPN connectivity, which is used to tunnel voice traffic. The essential ports are UDP 500 (IKE), UDP 4500 (NAT-Traversal), and often IP Protocol 50 (ESP). Ensuring these, along with proper SIP signaling (UDP/TCP 5060), are open on restricted networks enables the service.
UDP 500: Used for IKE (Internet Key Exchange) to establish the secure VPN tunnel.
UDP 4500: Used for NAT-Traversal (NAT-T) to allow IPSec traffic through home/public routers.
IP Protocol 50 (ESP): Encapsulating Security Payload, crucial for encrypting the data.
If calls still fail, check for firewall restrictions on UDP traffic and ensure your router allows IPSec pass-through.
Thank you for your message, and I’m sorry for the inconvenience you’re experiencing with Wi-Fi calling.
I understand that this issue only occurs with your ID SIM, and that Wi-Fi calling worked previously with Vodafone on the same Wi-Fi network. We’ll need to check your account settings and the provisioning for Wi-Fi calling to ensure everything is correctly enabled on your ID SIM.
Please send us a private message so we can securely access your account and investigate this further.
