The DrayTek VigorBX 2000 is compatible with SIP trunks provided by the ITSP (Internet Telephony Service Provider) Gamma Telecom.
This ITSP typically uses IP Authentication for their SIP trunks, which are linked to a fixed public IP address and do not use a SIP registration to authenticate access to the SIP trunk.
This guide assumes that the WAN interface of the VigorBX 2000 has been configured and the PBX system is connected directly to the internet connection with a fixed public IP address that Gamma have associated the SIP trunk with.
The way that the number is presented to the PBX system is significant because the trunk does not use registration; if the PBX system does not recognise the number presented or it is in an unrecognised format, the VigorBX 2000 will reject the incoming call because it is unable to route that call without a matching number configured in either a SIP Trunk or SIP Alias number.
The documentation supplied by Gamma would indicate whether the number is presented in national format (i.e. 05515552860) or international format (i.e. +445515552860)
Important Note: The SIP trunk will usually use UDP port 5060 for both inbound and outbound SIP traffic while the VigorBX 2000 uses UDP port 5070 to receive SIP calls. This means that the PBX system will not be able to receive calls unless the SIP trunk is reconfigured so that Gamma sends SIP packets to UDP port 5070. With default settings the VigorBX 2000 cannot use UDP port 5060 to receive SIP Trunk traffic because it uses this port for SIP Extension Registrations.
There are two ways to configure this:
Configure the SIP Trunk on the PBX system, go to [IP PBX] > [Trunks] > [SIP Trunk] and select an available Index number:
In that SIP Trunk index, configure these settings:
The remaining settings are not specific to this ITSP and can be configured as required.
Click OK to save and apply these settings.
Once the Gamma SIP Trunk is configured with the PBX system and the SIP port and IP address settings are correct, the PBX will handle calls as specified by the Answer Mode of each SIP Trunk. This can be used to route calls to the Auto Attendant, Hunt Groups or individual Extensions. Usage of the Answer Modes is explained in this guide: Routing Incoming Calls on the VigorBX 2000
Extensions registered with the PBX system can make calls using the SIP Trunks either by dialling the trunk number then dialling the desired number or by being routed using the Dial Plan facility. This requires that the extension has permission to use the trunk to make outgoing calls. Configuration of the PBX system to make outgoing calls is explained in further detail in this guide: Making Outgoing Calls with the VigorBX 2000