Packet arrival and buffer statistics in a packet switching node

Abstract

Packet multiplexing or switching systems split incoming customer messages into fixed length packets. Within a packet switching system information is transferred packet by packet. In this paper a model for a packet switching node is investigated. Terminals are connected to the node by local loops. In the model incoming messages are quantized into packets and completed packets are transferred to the desired outgoing trunk. Buffering techniques are applied to obtain high trunk utilization. In the model each trunk has a dedicated buffer which stores packets queueing up for transmission. First the statistics of packet arrival at a trunk buffer is analyzed by investigating the process of quantizing messages which arrive dispersed and overlapping in time. Then buffer requirements and overflow probabilities are derived as a function of local loop and trunk speeds and for various packet sizes.