Question One

Suppose TCP is used over a lossy link that loses on average one segment in four. Assume the bandwidth delay window size is considerably larger than four segments, i.e., the link should accommodate more than 4 segments.

1. What happens when we start a connection? Do we ever get to the linear increase phase of congestion avoidance?
2. Without using an explicit feedback mechanism form the routers, would TCP have any way to distinguish such link losses from congestion losses, at least over the short-term?
3. Suppose TCP senders did reliably get explicit congestion indications from routers. Assuming links as above are common, would it be feasible to support window sizes much larger than four segments? What would TCP have to do?