I have a SIP trunk configured on callmanager 4.1. This SIP trunk connects to an outbound dialer. This works fine, but is seems that I can have only 24 concurrent calls on the SIP trunk.
Is this correct, or is there a parameter to change this?
I've found that mtp can still be brought in, even when this is unticked. Use RTMT to confirm if mtp resources are being used. If they are, then if I remember right there are only 24 software mtp per server. In service parameters, under Clusterwide parameters - sip device: there is a field : 'fail call over sip if mtp allocation fails' if this is true, then this could be your problem.