I've got a BCM1000 3.7 with IP trunking licence working with a BCM 50 with SIP trunking licence and MCDN licence. I can call extensions and use the PRI on the BCM 50 from the 1000 extensions, but when calls are placed from the BCM 50 back to or through the BCM1000 the call drops. By turning on detailed release reasons, I get the messages "incompat dest" on the BCM1000 and "protocol error" on the BCM 50. Calling an extension on the 1000 will get the phone ringing, but when the call's answered, it drops with the messages I stated. I've played with some settings and I'm stumped for answer? Any ideas? Does H323 settings for ports have anything to do with SIP trunks?