just use the Obi Dashboard Device Configuration
Click on settings gear for SP1 or SP2
Click on Next under OBiTALK Compatible Service Providers
Click on Accept in the Emergency Service Calls
Click on Generic Service Provider
In the Configurations Name box change "Generic Service Provider" to "Vestalink"
In the Service Provider Proxy Server box put-
sms.intelafone.comIn User Name box put in your 4 digit Vestalink User number
Put in your password
If you want this to be the primary line for outgoing calls, check the box
then Click on Submit