LambdaStream is a streaming-version of RBUDP. It is an application-layer data transport protocol aiming to support high bandwidth gigabit-level streaming for applications in OptiPuter. Its key characteristics include a combination loss recovery and a unique rate control. The protocol uses the combination loss recovery to offer choices of either guaranteed reliable delivery or unreliable delivery, and uses the rate control scheme to avoid incipient congestion and decrease jitter by avoiding packet loss inherent in other congestion control schemes.

Currently, NS2 simulation of LambdaStream is done and shows the predicted results. An experiment on 10Gbps link from Chicago to Amsterdam shows it achieves over 4Gbps throughput whenever payload is high or low, whereas RBUDP performs poor when payload is low (Iperf measurement shows that UDP achieves about 5.6Gbps on this link). Experiments over a 4Gbps link from Chicago to Amsterdam are under way.