Path capacity measurement and congestion control in heterogeneous network
Zou ZiXuan · 2006
The Internet is an open and heterogeneous architecture that consists of different transmission medium, diverse platforms and applications.Network capacity has increased tremendously over the past decade.However, network applications and users have also grown tremendously.The end-to-end throughput of an application is dependent on the bottleneck link capacity along the path as well as the application transport protocol.In our research we have firstly focused on how to determine the path capacity (the capacity of bottleneck link).Active measurement techniques like Packet Pair (which derive from the principle of self-clocking in TCP's congestion control) have to be used to determine the path capacity.One of the major issues is maximizing the statistical correctness for measurement result.We proposed a new end-to-end based measurement technique, called Packet Triplet, to achieve a higher probability of finding the path capacity.A new filtering technique is introduced into Packet Triplet to further refine such measurement approach.It has shown better performance in terms of accuracy even in heavily loaded networks.Next, we investigated the performance of TCP transport protocol.TCP is widely accepted as the transport layer protocol in today's Internet.It makes up a large proportion of the traffic on the Internet.However, with the diversity of last mile network characteristics, e.g.wireless environment, the efficiency and effectiveness of the protocol have been greatly affected.This is especially so in the large and pervasive deployment of wireless access network.The great success of TCP is largely due to its end-to-end congestion control scheme, which is designed for avoiding congestion collapse and achieving fairness