Multi-path TCP congestion control method based on packet transmission delay

Abstract

The invention provides a multi-path TCP congestion control method based on packet transmission delay. The method includes the following steps that round-trip transmission delay rttr of a current packet is measured through substream r, and a base delay base RTTr is updated according to the rttr; the queuing delay qr of packets is calculated through the substream r according to the rttr and the base RTTr, and the number diffr of the packets queuing currently is estimated according to the qr; whether the diffr is smaller than a control parameter alpha r is judged, if the diffr is smaller than the alpha r, congestion windows cwndr of the substream r are increased linearly, if the diffr is larger than the alpha r, the congestion windows cwndr of the substream r are reduced linearly, and if the diffr is equal to the alpha r, the congestion windows cwndr remain unchanged; the current data transmission rate is estimated by means of the substream r according to the cwndr and the rttr, and the control parameter alpha r is updated in real time according to the data transmission rate. The method has the advantages that calculation cost is low, load balance granularity is small, compatibility is high and expansibility is high.

Description

technical field [0001] The invention relates to the technical field of the Internet, in particular to a multi-path TCP congestion control method based on packet transmission delay. Background technique [0002] With the evolution of the Internet and the development of network access technologies, more and more end systems have the characteristics of multi-homing, that is, they can use services provided by multiple ISPs to access the Internet at the same time. Because of having multiple network interfaces, multihomed hosts are often configured with multiple IP addresses. By using different IP addresses, multi-homed hosts can transmit data on different paths. This feature provides a material basis for designing multi-path TCP protocols. A multi-path TCP flow consists of several sub-flows, and each sub-flow uses a different IP address, so data can be transmitted through different paths. The sender dynamically adjusts the transmission rate of the sub-flow according to the chan...

AI Technical Summary

Problems solved by technology

From the network point of view, the behavior of each sub-flow of multi-path TCP is almost the same as that of traditional single-path TCP, but this similarity does not mean that multi-path TCP is a simple aggregation of multiple sub-flows. There are two reasons: one , the data transmission behavior of multiple sub-flows is not independent, but should be coupled with each other to realize the migration of traffic from congested paths to non-congested paths; second, multi-path TCP should coexist friendly with traditional single-path TCP, in other words , on the bottleneck link, the bandwidth obtained by a multi-path TCP flow should have nothing to do with the number of sub-flows, otherwise the performance of the traditional single-path TCP flow will be degraded

Designing a suitable congestion control algorithm is the key to achieving the above two goals. Since the traditional algorithm is only suitable for the data transmission requirements of single-path TCP, there is currently no new congestion control algorithm designed for multi-path TCP.

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