If you want to be able to select the SIM for outgoing call, then it can be done with "technical" prefix which is removed by the gateway before dialling the number to GSM/UMTS networks.

Example: You want to dial number 789456123, so instead you will send to the gateway 01789456123 to select SIM1. The gateway will cut 01 and dial 789456123 through SIM1.

The guide is following this example for 2 channel 2N VoiceBlue Next.

Settings on PBX side

You will have to set your PBX to add following prefixes (or other) based on your requirements

• 01 to dial through SIM1

• 02 to dial through SIM2

Settings on VoiceBlue Next

Gateway configuration/GSM Group Assignment - put each module inside different Outgoing group

Gateway configuration/Prefixes - set different technical prefix in each prefix list. I am going to configure 2 channel gateway. I will set just 2 prefix lists.

Prefix list 1

Prefix list 2

Avoid settings bellow. "/" is a indeterminate character which allows to skip Table of replaced prefixes. The beginning of the called number is then compared only with the right table. When you enter 0 in the right table, the gateway would dial 02789456123 instead of 789456123 as we wish.

Gateway configuration/LCR Table - interconnect prefixes with outgoing groups (which represent specific module/SIM card)

Click Add and fill Prefixlist 1 and Outgoing GSM group 1:

Click Add and fill Prefixlist 2 and Outgoing GSM group 2:

Save the result which must look like this:

Now everything is set. Make a call to verify settings.