***** tahoe-dynamic-demo.txt*******


A demo to illustrate the dynamic scenario using tcp tahoe. The
topology consistes of 5 nodes
0-2 and 1-2 are fast links sending at 8Mb with a delay of 5ms.
2-3 and 2-4 are slower links sending at 800Kb with a delay of 100ms.

TCP connections are setup between nodes 0&3 and nodes 1&3.
There is one ftp sources at node 0(brown pkts for data & ack) and node
1(blue pkts for data & ack) each.
Routing updates are in black.

simulation strats at time 0.5 when src 1 starts sending data to 3.
link 2-3 goes down at time 0.824 (shown in red).

src 0 also starts to send pkts at time 1.0 to receiver 3.

with the link going down src 1 loses the pkts and goes back to slow-start while src 0
rapidly increases the window size and goesinto congestion avoidance
phase pumping large no. of pkts into the network.src 1 continues conservatively.
with link 2-3 down all pkts are send via 2-4 and 4-3.

The link 2-3 comes up at 3.53.

with the coming up of link both the sources start pumping data onto the
link 2-3. The buffer at node 2 fills up and pkts get dropped for both
src 0 as well 1. both go back to TCP's slowstart phase.

Here the interesting behaviour of the network to note is that the coming
up of link 2-3 actually causes pkts to be dropped as opposed to
increasing the efficiency of the network as one would normally assume.