Wi-Fi calling on DrayTek routers

Wi-Fi calling is the process of creating an IPSec vpn between a mobile phone and a network provider such as EE and Vodafone to get better quality calls in areas where the coverage may be poor.

With Draytek routers, Wi-Fi calling should work with no configuration, however if users have issues with Wi-Fi calling working the below can be implemented as troubleshooting steps:

Things to check:

1. Wi-Fi calling can be affected by hardware acceleration. If possible, try disabling hardware acceleration for IPsec first to prove the issue.

2. If it’s not possible to disable hardware acceleration due to the customer requiring the extra speeds the option provides, turn off the IPSec hardware acceleration for TCP and UDP.

3. If the customer needs the IPsec hardware acceleration and doesn’t want to disable it you can give the mobile device a static IP using “Bind IP to MAC” function, enable the Exception list in hardware acceleration and add the device to the exception list on the hardware acceleration tab.

4. If the firewall is blocking the connection due to custom firewall rules the customer has enabled, allow ports 4500 and 500 through firewall (Outbound only) by creating a LAN to WAN rule and adding the ports 4500 and 500 as service objects to the filter rule, make sure to set the filter rule to pass immediately. Below is the example as a service type object that I created for 4500 that then is applied to a LAN to WAN rule.

5. If the customer has specific firewall rules in their firewall that block incoming or outbound traffic and it still doesn’t work with the above changes, the customer will need to contact the network provider (e.g. EE, Vodafone) and find out the list of IP’s that they use for Wi-Fi calling, these IP’s can then be added to the firewall filter list as a LAN to WAN and WAN to LAN rule. Will need both rules to have a pass immediately on them.