Abstract

Network managers implementing Fast Ethernet LAN solutions may, at times, need more than 100 Mbit/s between a server and a switch, or between switches. Short of migrating servers to Gigabit Ethernet, one approach to achieving higher bandwidth with existing LAN topologies involves link aggregation or “trunking.” Link aggregation is an emerging standard for grouping multiple LAN connections to function as a logical link. 

To verify the performance and interoper-bility of different combinations of Fast Ethernet link aggregation products, Sun Microsystems, Inc. commissioned The Tolly Group to test link aggregation using Sun’s SBus Quad FastEthernet Adapter. The adapter connected to switches from Bay Networks, Inc., Cabletron Systems, Inc., Cisco Systems, Inc., Extreme Networks, Foundry Networks, Inc., Lucent Technologies Inc., and Plaintree Systems, Inc. Testing was performed in March and April 1998. The tests examined connectivity over different trunk configurations, application throughput, and automatic recovery from link failure. 

Interoperability testing involved verifying connectivity between the SBus Quad FastEthernet Adapter and each of the switches under test for trunks comprised of two and four Fast Ethernet links. Performance testing focused upon application throughput across trunks comprised of four Fast Ethernet links. Network recovery testing involved verifying and measuring automatic recovery from a failure of one link in the trunk.