If you want to limit channels you would need to do that outside A2Billing. Send the call to this context:
Code:
[unld-in-a2-45565489240]
exten => _X.,1,Set(GROUP()=channel-a2-45565489240)
exten => _X.,2,GotoIf($[${GROUP_COUNT()} > 25]?99)
exten => _X.,3,Goto(a2billing-did,${EXTEN},1)
exten => _X.,4,Hangup(16)
exten => _X.,99,Busy()
Have a look at this line:
Code:
exten => _X.,2,GotoIf($[${GROUP_COUNT()} > 25]?99)
"25" means it is limited to 25 concurrent calls. "99" is where the call is sent when all channels are in use. In this case, it goes to a busy signal
Pay per minute providers typically give you unlimited channels because you are paying per minute. Unlimited DID providers normally set a limit on how many concurrent calls you can use, regradless of bandwidth
If you want some good rates just PM me - we offer special rates to calling card providers