The use of private voice networking trunks between IP500 control units and other systems requires voice networking channel licenses within the IP500. This applies to H323 IP trunks configured on the IP500 including IP trunks being used for an IP Office Small Community Network (SCN). A voice networking license is also required for the use of trunks configured to for QSIG operation. On H323 IP trunk, a license instance is consumed for each simultaneous outgoing call (incoming calls do NOT consume a license). On QSIG trunk, the number of calls is limited by the trunk type rather than available licenses.