Traffic analysis for IP telephony

There is a great interest today in voice communication over the Internet (VoIP) with a high level quality of service (QoS). Our objective in this paper is to assess to what extent today´s Internet is meeting this expectation. This work presents H.323 traffic analysis in the scenario where two LANs are connected through the Internet. For tests, series of H.323 calls between two endpoints were established, employing IP commercial cards and an Ethereal protocol analyzer for the packet reception. During the tests were taken into account a set of parameters such as: coded type, packet size (ms), and the voice activity detection. Relationships between the metrics: delay, jitter and packet loss were proved; considering real VoIP scenarios, and different types of codecs.