How can I see tcp slow-start flow control in the wireshark.. I transfer a file (100 M) between two computers on filezilla client/server to see how the window size increase but I didn't see it .. what should I do ?? asked 20 Feb '13, 04:38  Maher Moualla |
One Answer:
Slow-start is not negotiated or explicitly exchanged between hosts. It is a host-internal back-off mechanism to not saturate the bandwidth. The congestion window is therefor only known to the host and not transmitted over the network. The only way to "see" the slow-start control is by looking at the tcptrace Time Sequence graph (Statistics -> TCP StreamGraph -> Time-Sequence Graph tcptrace). It should have an exponential shape at first and then turn into a linear line (assuming no packet loss and constant RTT). You can also see the mechanism by looking at the bytes_in_flight field. It will stay low at first and will exponentially increase for a while. See also: http://en.wikipedia.org/wiki/Slow-start answered 20 Feb '13, 04:57  SYN-bit ♦♦ |
