1. Go to Settings → PBX → Trunk, Click to add a VoIP trunk.
2. Select protocol and trunk type.
3. Input the VoIP information which is provided by the ISP. For example:
Provider Name: Chinamobile
Hostname/IP: the registration IP given by the ISP (e.g. 22.214.171.124)
Domain: The domain server given by ISP (e.g. ims.fj.chinamobile.com)
Username: the username given by ISP (e.g. email@example.com )
Password: the account password given by the ISP
From user: the trunk number given by the ISP (e.g. +86592111111)
4.For more details please refer to S-Series VoIP PBX Administrator Guide.