The utility of characterizing the buffer of network devices in order to improve real-time interactive services

Abstract

The behaviour of the routers' buffer is of primary importance when studying network traffic, since it may modify some characteristics, as delay or jitter, and may also drop packets. As a consequence, the characterization of this buffer is interesting, especially when real-time flows of interactive services are being transmitted. If the buffer characteristics are known, then different techniques can be used so as to adapt the traffic: multiplexing a number of small packets into a big one or fragmentation. This work presents a study of how to determine the technical and functional characteristics of the buffer of a certain device (e.g. size, input and output rate and others characteristics related to its behaviour), or even in a remote node. Two different methodologies are considered, and tested on two real scenarios which have been implemented; real measurements permit the estimation of the buffer size, and the input and output rates, when we have physical or remote access to the "System Under Test". In case of having physical access, the maximum number of packets in the queue can be determined by counting. In contrast, if the node is remote, its buffer size can be estimated. We have obtained accurate results in wired and wireless networks.