Performance measurement of integrated voice/data on CSMA/CD network using orthogonal array methodology

The measurements that were carried out to determine the performance of the AT&T StarLAN for integration of voice and data are described. StarLAN is a local area network with star topology that uses the CSMA/CD protocol for medium access. For performance measurement, a systematic method based on orthogonal arrays was used. These measurements show that voice and data can be integrated on StarLAN with good grade-of-service, if the total load does not exceed 6 Mbps. This is true for any data packet size and any end-to-end delay up to 4 mu s. For voice-only terminals, this load corresponds to about 50 to 55 simultaneous active voice stations. For more than 6 Mbps acquisition time, and consequently packet loss, increase sharply due to multiple collisions and deferrals. For interactive data applications, echoplex delay meets the objectives if the load does not exceed 7.5 Mbps.<<ETX>>