Oudbound carriers

Hi all,

I’ve connected VOIP GSM GW, and i use to make outbound calls, but I have only 4 SIM cards in it, so what I need in case of overflow to make out call via PRI (ZAP/XXX).

I have seen that GSM GW can be configured (SIP) to return specific error code so I’m thinking about implementing hangupcause function (but don’t know really how)

Any ideas?


It might be best to set a maximum on the number of calls across the trunk group going to the GSM gateway and then if this is exceeded send the other calls to the ZAP group assigned to your ISDN.

yes, but I didn’t explain exactly what it is. External IVR sends which number to call (there are total 5 of them). But they are called randomly, sometimes all 5 at same time sometime only one. So I need to call first trough GW (zero cost) and than if needed trough ZAP