MSRT: Multi-Source Request and Transmission in Content-Centric Networks

In Content-Centric Networks (CCN), multiple routers may cache the same content, which makes it possible to retrieve the content chunks in parallel. In this paper, we propose Multi-Source Request and Transmission mechanism (MSRT) for CCN. We develop a MinMax problem to compute the optimal solution to retrieve all the chunks from multiple sources in the shortest time. We prove that the problem is NP complete and thus design a fully polynomial-time approximation algorithm to solve this problem. However, the previous works on multipath congestion control cannot be directly employed in MSRT. Therefore, we then propose the Half eXplicit Congestion Protocol (HXCP) to control the request/transmission pace in MSRT. To demonstrate the performance of MSRT, we construct comprehensive experiments. The results show that 1) our scheme reduces the content transmission time to at most 80%; 2) our multipath congestion control scheme HXCP effectively avoids congestion, improves the throughput and guarantees the fairness in the multi-source/multipath scenario.