22/25

Combined B/IP Routers and BBMDs

While the functions of BBMDs and of BACnet routers are entirely distinct, nothing precludes the implementation of BBMD functionality and router functionality in a single physical device.

Now let's look at how B/IP routers work...

B/IP routers adhere to the requirements of Clause 6 with the following differences:

• The physical ports of Clause 6 routers are replaced by logical ports. Each logical port is identified by the unique B/IP address of the port's connection to the B/IP network served by the router.

• The term "directly connected network" in Clause 6 implies a physical LAN connection between a LAN segment and a physical router port. In this clause "directly connected network" is extended to mean any B/IP network from which a router can receive local broadcast or IP multicast messages. Such networks are: the B/IP network on which a router resides by virtue of having an IP network number in common with one of the IP subnets comprising the B/IP network; a B/IP network in which the router participates as a member of an IP multicast group; or a B/IP network in which a router participates by having registered as a foreign device with a BBMD serving that network.

• Networks that are not directly connected are called "remote networks." Remote networks, whether B/IP or non-B/IP, may be reachable by communicating using B/IP with a router serving the remote network.

22/25