Measuring Network Performance

This wiki page contains the tutorial of measuring network performance.

Authors:

Artur Minakhmetov, Telecom Paris : artur.minakhmetov[at]telecom-paris.fr
Michael Sherman, Rutgers University : msherman[at]winlab.rutgers.edu

Last Updated: 26 June 2019

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Description

Cosmos test-bed provides a set of different network interfaces with different speed and rates. In this tutorial we will show how to measure the network performance.

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Context

This tutorial is based on topology and settings described in the optical network tutorial.

This example includes a server srv4-lg1 with connected to it tengigabitethernet 1/34 and joined with twentyFiveGigE 1/¼ on vlan 124. Binding tengigabitethernet 1/32 with twentyFiveGigE 1/¼ is performed the same way as in the optical network tutorial.

The server srv4-lg1 has an IP address assigned to it 192.168.1.4 on eno1 interface.

For simplicity, the Calient Switch S320 connects tengigabitethernet 1/34 with tengigabitethernet 1/32/1 through direct optical connection: 5.7.4←→5.7.6

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Measurement

Measurements are preformed through a command line tool iperf. Examples and descriptions of its operation could be found ​here.

• Set srv1-lg1 as a server:

native@srv1-lg1:~$ iperf -s   
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)

• Set srv4-lg1 as a client with sending traffic to srv1-lg1:

native@srv4-lg1:~$ iperf -c 192.168.1.1   
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[  3] local 192.168.1.4 port 35486 connected with 192.168.1.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  11.0 GBytes  9.42 Gbits/sec

• This measurement shows that the it's possible to have 9.42 Gbits/sec of bandwidth.

• Previous measurement creates a TCP connection. In order to test UDP traffic, a bitrate of UDP traffic has to be specified through and option -b. UDP traffic is specified through an option -u. Results of UDP traffic test are below :

Server side:

native@srv1-lg1:~$ iperf -s -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size:  208 KByte (default)
------------------------------------------------------------

Client side:

native@srv4-lg1:~$ iperf -c 192.168.1.1 -u -b 9gbps
------------------------------------------------------------
Client connecting to 192.168.1.1, UDP port 5001
Sending 1470 byte datagrams, IPG target: 1.31 us (kalman adjust)
UDP buffer size:  208 KByte (default)
------------------------------------------------------------
[  3] local 192.168.1.4 port 33737 connected with 192.168.1.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  9.77 GBytes  8.39 Gbits/sec
[  3] Sent 7134255 datagrams
[  3] Server Report:
[  3]  0.0-10.0 sec  9.30 GBytes  7.99 Gbits/sec   0.000 ms 342498/7134255 (0%)

• UDP traffic measurements show possible bandwidth of 7.99 Gbits/sec. This result could be ameliorated through specific settings potentially.

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Conclusion

In this tutorial we showed how it's possible to measure network performance and verify 10Gbit possibilities of optical transceivers achieving 9.42 Gbits/sec for TCP traffic and 7.99 Gbits/sec for UDP traffic.