Why can’t I make phone calls using the ATA with a Draytek ADSL router?
The Draytek Vigor series of ADSL routers have a feature known as a SIP Application Level Gateway (ALG).
This ALG has some bugs that makes it incompatible with the Wi-Manx ADSL service. The ALG on the Draytek router can be disabled as follows;
- Update the firmware to the latest version (see www.draytek.co.uk)
- Telnet to the router’s IP address
- Enter the router admin password
- Enter the following command “sys sip_alg 0″
- This will disable the ALG on the Draytek and make the VoIP service function as normal