Investigation of the Voice Transmission Characteristics over Internet

Abstract

There are examined the data transmission network parameters, important to support real-time voice traffic. Focused purely on the network packet loss probability and delay, that is critical to VoIP operation. For network performance analysis is used the classical M/M/1 and M/M1/S queueing systems. Data packets to the network node arrive according Poisson process and are served by a single server with an exponential transmission time distribution. The packet arrival rate λ and packet transmission rate µ in each node do not depend upon the number of data packets in the network node. In M/M/1/S model, the node can accommodate only S data packets including the one being in transmission. The state transition diagrams for both models are taken. The various network node performance measures important to VoIP operation, such as an average waiting time spent in the queue, the packet loss probability, the average number of packets in the waiting queue, the average number of packets at the transmission facility are computed. End to end path delay and packet loss probability is estimated for network consisting N nodes. Some calculated network performance measures are presented. Ill. 10, bibl. 6 (In Lithuanian; summaries in Lithuanian, English, Russian).