Sometimes calls are dropping

- Verify you Internet Connection by continuously pinging (Start -> Run -> cmd -> ping -t sip.voicemailtel.net) sip.voicemailtel.net to see if you have a steady connection to our servers;

- Verify that your phone / adapter has been updated to its latest firmware;

- If you are running your phone behind a NAT firewall that is SIP aware, packet mangling may occur;

- If you have other IP handsets or ATAs, check if they are also configured with the same terminal ID. This could create registration conflicts and sudden call drops as the server will only allow one terminal ID to register at a time.