A scalable RTT estimation algorithm for multicast congestion control

Round trip time (RTT) is critical to ensure that multicast flows behave in a TCP-friendly manner. We present a multicast RTT estimation algorithm which solves feedback implosion and clock synchronization. Each receiver schedules an exponentially distributed timer to suppress feedback. Non-suppressed receivers use round trip estimation to get an accurate RTT. Suppressed receivers can either use a one-way measurement to get an estimation of RTT or request a non-suppressed neighbor in the same LAN to share the newly calculated RTT.