Thanks for the info. I would like to know that if there is BBMD in our local network another BBMD is in a public network then the network numbers of both the BBMDs shall be same to talk to each other? If a Foreign device is in a public network does it need to be assigned with a different network number to talk to the BACnet Devices in the local network? We are using all BACnet I/P devices only. Please make me more clear on this topic.