Existing transport layer protocols such as TCP and UDP are designed specifically for point-to-point communication. The increased popularity of peer-to-peer networking has brought changes in the Internet that provided users with potentially multiple replicated sources for content retrieval. However, applications that leverage such parallelism have thus far been limited to non-real-time file downloads. In this article we consider the problem of multipoint-to-point video streaming over peer-to-peer networks. We present a transport layer protocol called R2CP that effectively enables real-time multipoint-to-point video streaming. R2CP is a receiver-driven multistate transport protocol. It requires no coordination between multiple sources, accommodates flexible application layer reliability semantics, uses TCP-friendly congestion control, and delivers to the video stream the aggregate of the bandwidths available on the individual paths. Simulation results show great performance benefits using R2CP in peer-to-peer networks.