# Starting the NOCC TCP

Once all ISDN protocol stack instances are created, start a NOCC TCP on each B channel context. This TCP puts the context in a state where voice or media functions can be used without call control.

Call nccStartProtocol for each B channel context, specifying NOCC in the protname argument.

When nccStartProtocol is called, NCCEVN_STARTPROTOCOL_DONE is returned. If the NOCC TCP is started successfully, the event value field contains CTA_REASON_FINISHED. Otherwise, the value field contains another reason code.