5. Congestion control: TCP versions

As we have seen, the 3.1 sliding window technique ensures that a "fast" TCP sender does not flood a "slow" TCP receiver. However, when the bottleneck is not in the receiver but in the network nodes, this mechanism is unable to prevent router memories from becoming saturated, leading to packet loss. This congestion may be caused either by the presence of low-speed links along the route followed by the connection, or because the rate of packet arrival in a router's...