Fast dynamic measurement of bandwidth in a TCP network environment

Abstract

The fast dynamic measurement of bandwidth in a TCP network environment utilizes a single pair of packets to calculate bandwidth between two entities on a network (such as the Internet). This calculation is based upon the packet-pair technique. This bandwidth measurement is extremely quick. On its journey across a network, communication devices may delay the packet pairs. In particular, TCP networks have two algorithms designed to delay some packets with the goal of increasing the overall throughput of the network. However, these algorithms effectively delay a packet pair designed to measure bandwidth. Therefore, they distort the measurement. These algorithms are Nagle and Slow Start. The fast dynamic measurement of bandwidth implements countermeasures to overcome the delays imposed by these algorithms. Such countermeasures include disabling the application of the Nagle Algorithm; minimizing the buffering of packets by sending a “push” packet right after the packet pair; and avoiding the Slow Start Algorithm by priming it with a dummy packet.

1 . A method for measuring bandwidth of a network connection between a sending entity and a receiving entity through an intermediate communication device, the method comprising:
 sending two bandwidth measurement packets back to back from the sending entity to the receiving entity to measure bandwidth of a connection between the sending entity and the receiving entity; and   prior to sending the two bandwidth measurement packets, sending at least one priming packet from the sending entity to reduce transmission delays of the intermediate communication device, wherein the priming packet is not used for the bandwidth measurement.