Comparison between the real and theoretical values of the technical parameters of the VoIP codecs

Abstract

The real values of the technical design parameters that voice codecs possess play a very important role when it is desired to size the bandwidth within a Voice over Internet Protocol (VoIP) communications network, so it is important to know these values. Thus, in the work presented below you get the real values of the most common technical design parameters that have of the voice codecs such as payload, bit rate, Packets Per Second (PPS) and frame size, through the Wireshark software for VoIP monitoring. For this, real VoIP calls were made through softphones applications and using different test scenarios. These applications were installed on smartphones and were configured with Session Initiation Protocol (SIP) accounts, where a set of 8 voice codecs was handled. This was done in order to find out if there are variations between the theoretical and real values of these parameters. The results obtained show that there are differences between these values. It is concluded that by directly using the theoretical bandwidth values of voice codecs, the number of users who could communicate at the same time in a VoIP network with SIP accounts would be oversized.