Abstract

The Tolly Group evaluated key performance aspects of token ring switches: aggregate frame throughput across a single stream (measuring throughput for 28-, 64-, 128-, 512-, 1024-, and 3,972-byte frames. The Tolly Group also tested switch performance for two, four, six and eight streams across various high speed uplinks, subjected each switch to numerous filtering and VLAN tests, and checked for RMON and LAN Network Manager support.

Switches from the following vendors were tested: Bay Networks, Cabletron, Cisco Systems, IBM, Madge Networks, and Olicom A/S.

In order to conduct single-stream performance tests, The Tolly Group used nearly a dozen Wandel & Goltermann Inc. DA-320 DominoLAN analyzers, specifically to take advantage of their accurate frame generation and traffic monitoring capabilities. The DA-320s each connected to a token ring MAU, which in turn was connected to a token ring switch under test operating at 16Mbit/sec. in half-duplex mode. The DA-320s also generated various traffic loads for uplink testing. The Tolly Group also employed Netcom Systems, Inc.'s SmartBits traffic generators for tests with high-density port traffic.

Invitations to participate in the testing were sent to all token ring switch vendors. The participating vendors funded this project, although The Tolly Group conceived and executed all tests independent of the vendors.