Enabling Efficient Communications with Session Multipathing

In this paper we report an investigation on potential session multipathing strategies that leverage the easy deployment of user space-based protocols. We devised an experimental session layer architecture to deal with multipathing and we implemented such architecture with 4 different libraries of asynchronous I/O processing for Linux systems: Epoll, Posix Threads, Posix AIO, and Libev. We discuss the evaluation of these implementations (a) by comparing them with the general kernel space solution, Multipath TCP (MPTCP), in an emulated network, and (b) by determining both the performance gain factor and the cost of resource consumption as function of the number of paths in a session. We found that Libev API, a full-featured and high-performance event loop, applied to the session multipathing enables an average good put gain factor of 1.62 faster per path added in a session, while its counterpart is of 2.23% of CPU utilization per path and it requires no more than 4 MB of RAM regardless the number of paths. We also observed that Libev-based multipathing allows overall efficiency slightly higher than MPTCP.