Utilizing spare network bandwidth to improve TCP performance

It is well-known that TCP Reno represents a performance bottleneck as the delay-bandwidth product increases. On high-bandwidth-delay links, the additive increase policy of one packet every RTT necessitates thousands of RTTs to reach full link utilization. This severely affects short TCP flows (most of the flows in the internet) as they cannot acquire bandwidth faster than “slow start” and waste precious RTTs ramping up even when bandwidth is available. XCP [2] addresses this problem by heavily modifying routers to explicitly tell the end-hosts about their fair share of network bandwidth. Fast-TCP [1] backs-off proactively without incurring any loss but cannot quickly ramp-up as the fair share increases.