Priority service disciplines and voice cell discarding schemes in ATM networks

Priority service disciplines and congestion control schemes for voice and data multiplexing with bursty inputs in asynchronous transfer mode ATM/SONET broadband networks are presented. The authors consider dynamic mapping of ATM cells in the SONET payload. They propose separate buffers for voice and data to efficiently control the throughput of each traffic type. Transmission bandwidth is dynamically shared between voice and data to guarantee grade of service (GOS) requirements for each traffic type. A selective voice cell discarding scheme is also considered for voice-data integration. The effects of voice cell discarding on network performance for integrated voice and data systems were analyzed by simulation. The results showed that the priority service disciplines, in combination with the voice cell discarding scheme, were very efficient methods to guarantee a GOS requirement for voice. The cell discarding scheme was shown to reduce cell losses as well as delays for data. It was found that the performance for data can be significantly improved by imposing the thresholds at both voice and data buffers