Slow-start to Congestion avoidance:
>
> Another point: in your spreadsheet, you seem to be assuming that the TCP
> window will *double* on every round-trip until it reaches 64k. This doubling
> only happens during the slow-start phase, until the window size reaches a
> certain threshold (anyone have references for what a common threshold is?
There is no fixed threshold. The slow-start phase can go on until the cwnd
(current window) reaches the advertised window size if no loss or timeout
occurs. Slow start ends if a loss occurs or time out occurs (described in
RFC 2001)
> 8k?) -- after reaching that threshold, TCP switches into congestion-avoidance
> mode, where one packet is added to the window for every N packets received,
> where N is the current window size. So it actually takes much longer to get
> all the way to a full 64K window size. :^(
The duration depends upon the current status (congested or not) of the
network.
>
>
> A recent paper in IEEE/ACM Transactions on Networking might be of interest:
>
> Lakshman and Madhow, "The Performance of TCP/IP for Networks with High
> Bandwidth-Delay Products and Random Loss" IEEE/ACM Trans. Networking, vol 5,
> Number 3, pp.336-350, June 1997
>
> - -(-- John
Ravi
COMSAT Labs
This archive was generated by hypermail 2b29 : Mon Feb 14 2000 - 16:14:28 EST