SmartBridge: A Scalable Bridge Architecture
Chandramohan A. Thekkath
Compaq Systems Research Center
As the number of hosts attached to a network increases beyond what can
be connected by a single local area network (LAN), forwarding packets
between hosts on different LANs becomes an issue. Two common solutions
to the forwarding problem are IP routing and spanning-tree bridging.
IP routing scales well, but imposes the administrative burden of
managing subnets and assigning addresses. Spanning-tree bridging,
in contrast, requires no administration, but often does not
perform well in a large network, because too much traffic must detour
toward the root of the spanning tree, wasting link bandwidth.
This talk describes a new architecture, called SmartBridge,
that combines the good features of IP routing and spanning-tree
bridging. We have implemented the SmartBridge design for 10 Mb/s and 100 Mb/s
Ethernet LANs, using standard PC hardware with off-the-shelf network
interface cards and running our algorithms in software.
Our 100 Mb/s system runs at full link bandwidth.
This is joint work with Tom Rodeheffer (Compaq SRC) and Darrell Anderson
(Duke University).