Do I need to configure two different accounts in order for me to call from VOIP to PTCN and PTCN to VOIP? or same account?
Most accounts provide both inbound and outbound.
Not Clear, there are two configuration pages in the ATA, Do I need to setup two separate account for FXS and FXO ports? for inbound and outbound?
You connect your analog phone to the Phone Port (FSX).
If you have an OBi110 or an OBi2xx with an OBiLine adapter, you connect the Line Port (FXO) to a landline.
The OBi Land Line is pre-configured for N. America.
To manually configure a VOIP provider there are 2 sections you have to define.
Under Service Providers you define the provider's proxy name or address.
Under Voice Services you define the userid and password.
Depending on the provider the above will get you registered.
Voip providers usually support inbound and outbound calls.