In this lab we are going to see the differences of the three TCP variants.
Network Model
The network topology will consist of 4 nodes in an linear topology. The network is depicted in the following figure.
The technical characteristics of the network are the following
- All the links initially will have bandwidth of 1.5 Mbps, delay of 10ms and the nodes will have a Drop Tail queue, of which the maximum size is 10
- The Link B --> C will notice some packet loss (The specifications of the packet loss module will be given in the Simulation Scenario Section)
Simulation Scenario
The Events of the scenario are:
- In time 0 the simulation will start
- The FTP will start at time 0.5 with source A and destination D.
- At time 1.5 a UDP transmission starts between B and D with 1 Kbytes packets at the rate of 3 Mbps and ends at 3.5
- At time 5.0 the simulation will end
Deliverables
Turn in your .tcl file and a report that explains how the three TCP variants behave. You will have to plot for each of the above cases of TCP variant, how the congestion window changes through time. In your report you should have the 3 graphs and briefly explain the graphs, as well as the key characteristics of the TCP variantsHints
In order to succesfully complete the in lab assignment you will have to use commands and modules that we havent seen in previous labs. These modules and commands can be found inside the Skeleton file with detailed comments. These modules include: the creation of the loss link modules, the tracking of the congestion window size and how to switch between the three different TCP versions.Moreover, the following links are worth checking.