The four-channel 2N® VoiceBlue MAX has 4 FXS ports to connect exchanges or analog phones and also supports connection to VoIP network (via Ethernet port). Let´s imagine the scenario that you want to make calls from analog phones and route these calls to GSM network based on the prefixes (called number). But if the limits on SIM cards is exceeded or all GSM modules are busy, you will want to route these calls to VoIP interface – it means that the VoIP network will be a backup solution for outgoing calls.
Note: In this FAQ is assumed that your gateway is properly registered to any device of VoIP provider (another gateway, some PBX, etc.).
How to set up backup solution for calls from analog phones in 2N® VoiceBlue MAX gateway:
- First of all you have to set "Port modes" for FXS lines – it means how the calls from analog lines will be forwarded. Select the option "Use LCR table or VoIP as a fallback port" as shown on the picture below:
- In the next step it is necessary to specify prefixes which could be dialed. The GSM operators have e.g. in our country prefixes 6 and 7 and the length of the whole number is nine digits.
Note: You can also modify the called number in 2N® VoiceBlue MAX gateway – for this purpose you can use "Table of replaced prefixes" but it is not shown in the picture below.
- You can create up to 8 GSM outgoing groups, in these you are able to assign SIM cards which will be used for outgoing calls. In the "GSM group assignment" section you can define, which SIM card (GSM module) belows to which GSM outgoing group.
- Now you need to create LCR (Least Cost Routing) rule for defined prefixlist. In each LCR record you can select "prefix list" with specified prefixes and then choose one of eight created GSM outgoing groups that say through which outgoing group the call will be forwarded. You can also choose "Fallback port" that is in our example interface to VoIP provider – it means that if modules assigned to GSM group 1 is busy or SIM cards limit is exceeded, all calls will be routed via VoIP interface.