mscom_network_start

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision		 Previous revision
mscom_network_start [2014/05/13 14:51] – [Laboratory expirements] - added lab2 beckmanfmscom_network_start [2016/03/16 09:01] (current) – [Setup of the Linux test platform / USB Stick] - removed student laptop beckmanf
Line 5: Line 5:
 Details regarding tcp testing are here: [[http://www.linuxfoundation.org/collaborate/workgroups/networking/tcp_testing]]. Details regarding tcp testing are here: [[http://www.linuxfoundation.org/collaborate/workgroups/networking/tcp_testing]].
  
-==== Setup of the Linux test platform / USB Stick ====Ìý+==== Setup of the Linux test platform ====
-Ìý+
-Network tests are done with a network of Ubuntu Linux computers which are connected via an ethernet switch. Students laptops will be part of the setup. If you have a native linux installation, you can use that directly. Follow the steps in [[mscom_linux_setup|Master COM Linux test setup / USB Stick]]. If have a laptop which does not have a native linux installation, then you can use a bootable USB Stick which we provide. +
  
 +Network tests are done with a network of Ubuntu Linux computers which are connected via an ethernet switch. 
 ==== Laboratory expirements ==== ==== Laboratory expirements ====
  
Line 177: Line 176:
 </code> </code>
  
 +==== TCP configuration ====
  
 +=== Local memory restrictions ===
 +Set the maximum window sizes for tcp connections to 512000 Bytes. 
 +
 +<code>
 +sudo sh -c "echo 512000 > /proc/sys/net/core/wmem_max"
 +sudo sh -c "echo 512000 > /proc/sys/net/core/wmem_default"
 +sudo sh -c "echo 512000 > /proc/sys/net/core/rmem_max"
 +sudo sh -c "echo 512000 > /proc/sys/net/core/rmem_default"
 +sudo sh -c "echo 512000 512000 512000 > /proc/sys/net/ipv4/tcp_wmem"
 +sudo sh -c "echo 512000 512000 512000 > /proc/sys/net/ipv4/tcp_rmem"
 +</code>
 +
 +=== Initial TCP contention window size ===
 +
 +The following section shows how to change the initial contention window size to to 1 MSS. 
 +
 +<code>
 +fritz@ubuntu:~$ ip route show
 +default via 192.168.178.1 dev eth0  proto static 
 +169.254.0.0/16 dev eth0  scope link  metric 1000 
 +192.168.178.0/24 dev eth0  proto kernel  scope link  src 192.168.178.33  metric 1 
 +fritz@ubuntu:~$ sudo ip route change default via 192.168.178.1 dev eth0 proto static initcwnd 1
 +fritz@ubuntu:~$ ip route show
 +default via 192.168.178.1 dev eth0  proto static  initcwnd 1
 +169.254.0.0/16 dev eth0  scope link  metric 1000 
 +192.168.178.0/24 dev eth0  proto kernel  scope link  src 192.168.178.33  metric 1 
 +fritz@ubuntu:~$ 
 +</code>
 +
 +=== TCP Congestion avoidance algorithm selection ===
 +
 +The linux kernel provides several algorithms for tcp congestion avoidance. The following code shows how to figure out the available algorithms (here cubic and reno) and set and control the setting. In this example the congestion avoidance algorithm is switched from "cubic" to "reno". 
 +
 +<code>
 +fritz$ cd /proc/sys/net/ipv4/
 +fritz$ cat tcp_available_congestion_control 
 +cubic reno
 +fritz$ cat tcp_congestion_control 
 +cubic
 +fritz$ sudo sh -c "echo reno > tcp_congestion_control"
 +fritz$ cat tcp_congestion_control 
 +reno
 +</code>
  
  
  
  • mscom_network_start.1399985501.txt.gz
  • Last modified: 2014/05/13 14:51
  • by beckmanf