The Multi-path Utility Maximization and Multi-path TCP Design

TL;DR

This paper formulates a multi-path network utility maximization problem, approximates it for efficient solution, and develops compatible multi-path TCP protocols that ensure fairness and coexistence with existing TCPs.

Contribution

It introduces a novel approximation approach for the non-convex NUM problem and designs multi-path TCPs compatible with current protocols.

Findings

The proposed algorithms converge to the global optimum.

Multi-path TCPs are compatible with existing TCPs.

Simulations show fairness and coexistence among users.

Abstract

The network utility maximization problem (NUM) for multi-path is a problem which is non-strictly convex and non-separable. Using Jensen's inequality, we approximate the NUM to a strictly convex and separable problem which can be solved efficiently by the dual decomposition method. After a series of approximations, the result of the approximation problem converges to the globally optimal solution of the original problem. Moreover, because of the separable and dual-based natures of the proposed algorithm, we utilize the reverse engineering frameworks of the current TCPs to develop a series of multi-path TCPs which are totally compatible with current TCPs. The multi-path users using our protocols can run simultaneously with the single-path users using the current TCPs. The simulations of our Multi-path Reno on ns-2 show the compatibility and the fairness among multi-path and single-path users.