2 Simulation program » History » Version 26

Version 25 (MOURA, Ninon, 03/23/2016 12:53 AM) → Version 26/47 (MOURA, Ninon, 03/23/2016 12:57 AM)

h3. 2. Simulation program

h4. 2.1. Simulation

Fisrt simulation as been run without modem.

Line commands on PEP-right are described hereafter, note that commands for PEP-left are similar.

# Step 1 : Connexion in SSH to remote terminal.
~
ssh labo@192.168.0.200
~

# Super User Connexion in PEP-right as super user
~
sudo su
~

# Definition of p5p1 IP adresses of interfaces adress
~
ifconfig p5p1 192.168.2.2
~

Definition of p6p1 IP adress
~
ifconfig p6p1 p5p1 192.168.3.1
~

# Addition of Add space delay to user interface (p5p1)
~
tc qdisc add dev p5p1 root netem delay 600ms
~

# Test connection and delay
#
from 192.168.2.1 to 192.168.3.1
~
ping 192.168.3.1 -I 192.168.2.1
~


# Implementation of routing rules Re-routing rule to in order to use PEPSal. Indeed PEPSal uses port 5000, consequently TCP flow must be redirected on this port.
~
iptables -t mangle -A PREROUTING -s 192.168.2.1 --proto tcp --tcp-flags ALL SYN -j QUEUE
iptables -t nat -A PREROUTING -s 192.168.2.1 --proto tcp -j REDIRECT --to-port 5000
iptables -t mangle -A PREROUTING -d 192.168.3.1 --proto tcp --tcp-flags ALL SYN -j QUEUE
iptables -t nat -A PREROUTING -d 192.168.3.1 --proto tcp -j REDIRECT --to-port 5000
~

Display all rules to verify
~
iptables -t mangle -t nat -L
~

# Execution of

Proxy
PEPSal on port

~
pepsal -a 192.168.2.1
~

Then a TCP flow is simulated thanks to the iperf command.

h4. 2.2. Post processing

In order to get information on TCP packets, the tcpdump commmand is executed. The save option is run and data are collected in a file.pcap.
Command is:
tcpdump tcp -w fileName.pcap

# Files transfert from PC engine right to local computer
scp labo@192.168.0.201:Proj3/*.

The file generated by tcpdump command is compatibile with wireshark. Wireshark is a free network protocol analyzer. It lets you see what's happening on your network at a microscopic level. Thanks to this tool, we could compare with and without PEPSal:
* throughput,
* sequence number packets,
* windows size evolution.

Tests in terms of quality of usage, such as download a web browser, were planed. However due to difficulties in network configuration, those tests will not be run.