VoIP Congestion Control by changing packet size – Simulation

While I was pursuing my certificate in Computer Networking at Stanford University in 2005, I worked on a simulation which is the closest I got during my era as a student to have a paper that could be submitted for publication. The dynamics of the patent described in the patent No. US 6,421,720 regarding a “codec-independent technique for modulating bandwidth in packet networks” are investigated by means of simulations. The patent idea is that senders adapt their rate, by changing packet size, based on network load. Two sender-based rate algorithms, 2 RTCP versions, 2 codecs and several bandwidth sizes are studied in several scenarios combining all the variables. We evaluated these scenarios with an evaluation criteria composed of several items including voice quality via PESQ. We showed that the idea presented in the patent controls congestion, but that a mechanism to prevent oscillations is necessary at the sender-based rate adaptation algorithms studied.

The paper developed is available here