Sample H323 configuration with CUCM
! vty-async isdn switch-type primary-net5 ! ! voice rtp send-recv ! voice service voip allow-connections h323 to h323 allow-connections h323 to sip allow-connections sip to h323 allow-connections sip to sip supplementary-service h450.12 fax protocol pass-through g711alaw h323 no h225 timeout keepalive modem passthrough nse codec g711alaw redundancy sip registrar server expires max 3600 min 3600 ! voice class h323 1 h225 timeout tcp establish 3 call start slow ! ! controller E1 0/0/0 framing NO-CRC4 pri-group timeslots 1-31 ! controller E1 0/0/1 framing NO-CRC4 pri-group timeslots 1-31 ! controller E1 0/1/0 framing NO-CRC4 pri-group timeslots 1-31 ! interface Serial0/0/0:15 no ip address encapsulation hdlc isdn switch-type primary-net5 isdn incoming-voice voice no cdp enable ! interface Serial0/0/1:...