NIST Net Installation and Configuration Note

This document describes the steps needed to successfully install and configure NIST Net using the provided NIST Net distribution disc.

NIST Net is a network emulation package that runs on Linux. The NIST Net network emulator is a general-purpose tool for emulating performance dynamics in IP networks. The tool is designed to allow controlled, reproducible experiments with network performance-sensitive/adaptive applications and control protocols in a simple laboratory setting. By operating at the IP level, NIST Net can emulate the critical end-to-end performance characteristics imposed by various wide area network situations (e.g., congestion loss) or by various underlying subnet technologies (e.g., asymmetric bandwidth situations of xDSL and cable modems).

NIST Net by default is used to add latency, bandwidth limitations, packet loss or duplication, and other WAN characteristics on all IP traffic moving between the Ethernet ports of the system, while exclusions to this directive can be added on a per system basis.

Hardware Requirements

The following is the minimal hardware configuration required for a successful installation, configuration, and execution of NIST Net.

Note The distribution is based on Red Hat Linux, thus hardware used for this installation needs to be compatible with Red Hat Enterprise Linux 3.0.

Software Installation

Step 1

Insert the provided disc in the CD-ROM drive and boot up the workstation.

Step 2

When you see the Manual Disc Partitioning screen, select Auto Partitioning.

Step 3

Select Remove all partitions from this disc. (This is the default setting.)

Step 5

At the Time Zone Selection screen, select your time zone using the mouse.

System Configuration

Once the system has rebooted, log on using the root user (password is "actona") and configure the system's hostname, default gateway, and network interface cards. You do this by editing the files using vi, and then restarting the system as described in the following steps:

vi /etc/sysconfig/network

NETWORKING=yes

HOSTNAME=emulator

GATEWAY=

Save the file and exit by pressing ESC, Shift-;, typing wq at the colon prompt(:), and pressing the Enter key.

vi /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

BOOTPROTO=static

ONBOOT=yes

IPADDR=10.0.1.1

NETMASK=255.255.255.0

BROADCAST=10.0.1.255

Save the file and exit by pressing ESC, Shift-;, typing wq at the colon prompt(:), and pressing the Enter key.

vi /etc/sysconfig/network-scripts/ifcfg-eth1

DEVICE=eth1 
BOOTPROTO=static 
ONBOOT=yes 
IPADDR=10.0.2.1 
NETMASK=255.255.255.0 
BROADCAST=10.0.2.255

Save the file and exit by pressing ESC, Shift-;, typing wq at the colon prompt(:), and pressing the Enter key.

Launching NIST Net

./nistnet

If this is the first time you launch NIST Net, the package will build itself based on the hardware configuration.

Step 2

Once completed, you see a menu from which you can launch the emulation tool with different network settings.

Please select a preset from the following options: 
-------------------------------------------------- 
1:  40ms round-trip delay, T1 bandwidth, 0.5% packet loss 
2:  60ms round-trip delay, T1 bandwidth, 0.5% packet loss 
3:  80ms round-trip delay, T1 bandwidth, 0.5% packet loss 
4: 100ms round-trip delay, T1 bandwidth, 0.5% packet loss 
5: 120ms round-trip delay, T1 bandwidth, 0.5% packet loss 
6: 160ms round-trip delay, T1 bandwidth, 0.5% packet loss

7: Custom Settings 
8: Stop WAN Emulation 
9: Exit

Using the menu, you can set up the network environment with preconfigured values (1-6) or your own custom settings (7). To stop emulation altogether, use menu option 8. For examples, refer to the "Using NIST Net" section

Using NIST Net

Example 1

To set the network for 80ms round trip latency, with a T1 (1,544 Kbps) and 1/2%packet loss - select option 3 from the NIST Net menu. If the activation is successful, you see this screen.

3 
******************************** 
*  NISTnet Activation Script   * 
******************************** 
Clearing WAN table and loading NISTnet... 
Configuring NISTnet... 
Reading WAN table: 
cnistnet -a 0.0.0.0 0.0.0.0 --delay 40.000 --drop 0.5005 --bandwidth 197632 --drd 79 80 0 
Done. 
********************************

Activation of the script clears the current WAN table (line 1), configures NIST Net to the desired settings (line 2), and lastly displays the current WAN table (line 3). The current table consists of one entry - any IP to any IP going through NIST Net will be subjected to a 40 ms latency (a total of 80 ms round trip), �% packet loss and limited to a T1 bandwidth. In this example, the bandwidth value of 197632 bytes is derived from the following formula: T1 = (1,544 Kbits/sec) * 1024 = (1581056 bits/sec)/8 = 197632 bytes/sec.

Example 2

If you want custom settings, select option 7 on the NIST Net menu. You are prompted to enter your settings, as shown in the example below.

7 
Custom WAN Settings: 
-------------------- 
Enter bandwidth [bytes]: 
98816 
Enter one-way delay [millisec]: 
25 
Enter packet-loss [percent]: 
.25 
******************************** 
*  NISTnet Activation Script   * 
******************************** 
Clearing WAN table and loading NISTnet... 
Configuring NISTnet... 
Reading WAN table: 
cnistnet -a 0.0.0.0 0.0.0.0 --delay 25.000 --drop 0.2502 --bandwidth 98816 --drd 79 80 0 
Done. 
********************************

You are prompted to specify the bandwidth in bytes (line 1), a one-way latency in milliseconds (line 2) and the percent packet loss (line 3). Remember to press the Enter key after entering each value. In this example, NIST Net is set up to provide a 768 Kbps (�T1) line with a total of 50 ms round trip latency and �% packet loss. In this example, the bandwidth value of 98816 bytes is derived from the following formula: T1 = (1,544 Kbits/sec) * 1024 = (1581056 bits/sec)/8 = (197632 bytes/sec)/2.

Client & Server Configuration

In order for the WAN emulation tool to affect client and server network traffic (i.e., add latency, bandwidth limitation, etc.) at the emulated WAN edges, NIST Net should be treated as the router for both sides of the WAN. On each participating client or server, configure the default gateway to point to the relevant IP address of the NIST Net system.

This concludes the NIST Net WAN Emulation Tool installation and configuration. For more information, refer to the NIST Net website at http://snad.ncsl.nist.gov/itg/nistnet/

Note NIST Net is available online at http://snad.ncsl.nist.gov/itg/nistnet/index.html and is included in this distribution package for your convenience. Questions about NIST Net should be directed to nistnet-dev@antd.nist.gov. The software is provided as-is for use at your own risk. Cisco Systems, Inc makes no warranty of any kind, either expressed or implied, as to the results that may be obtained from the use of NIST Net, or as to the accuracy, reliability, or content of any information or service contained in or provided through the software.

Table Of Contents

NIST Net WAN Emulation Software
Installation and Configuration Note

Hardware Requirements

Software Installation

System Configuration

Launching NIST Net

Using NIST Net

Example 1

Example 2

Client & Server Configuration

Copyright � 2004 Cisco Systems, Inc. All rights reserved.

Table Of Contents

NIST Net WAN Emulation Software Installation and Configuration Note

Hardware Requirements

Software Installation

System Configuration

Launching NIST Net

Using NIST Net

Example 1

Example 2

Client & Server Configuration

Copyright � 2004 Cisco Systems, Inc. All rights reserved.

NIST Net WAN Emulation Software
Installation and Configuration Note