Exploring TCP Parallelisation for performance improvement in heterogeneous networks

TCP Parallelisation uses a set of parallel (modified or standard) TCP connections to transfer data for an application process. With standard TCP connections, TCP Parallelisation has been used to effectively utilise bandwidth for data intensive applications over high bandwidth-delay product (BDP) networks. On the other hand, it has been argued that a single TCP connection with proper modification can emulate and capture the robustness of TCP Parallelisation and thus can well replace TCP Parallelisation. A typical example is HSTCP, which can emulate the behaviour of a set of multiple standard TCP connections. However, through the analysis and the proposed use of TCP Parallelisation in this paper, we found that TCP Parallelisation has its unique merits, which cannot be emulated by a single-connection based approach. As a result, the single-connection based approach (such as HSTCP) may not be able to achieve the same effects as TCP Parallelisation, especially in heterogeneous networks and highly dynamic environments (e.g., high BDP networks combined with wireless access links). In this paper, we demonstrate some of these unique merits of TCP Parallelisation (namely, localisation of disturbances such as Fast Recovery, loss synchronisation between parallel connections and self-healing) over single-connection based approach in the heterogeneous environment.