Laboratory
LAB1
2
Network Design
Planning a Network with Different Users, Hosts, and Services
Objective
The objective of this lab is to demonstrate the basics of
designing a network, taking into consideration the users,
services, and locations of the hosts.
Procedure
Create a New Project
1. Start Riverbed Modeler Academic Edition ⇒ Choose New from the File
menu.
2. Select Project and click OK ⇒ Name the project <your
initials>_NetDesign, and the scenario SimpleNetwork ⇒ Make sure
that the Use Startup Wizard is checked ⇒ Click OK.
3. In the Startup Wizard: Initial Topology dialog box, make sure that Create
Empty Scenario is selected ⇒ Click Next ⇒ Choose Campus from
the Network Scale list ⇒ Click Next ⇒ Choose Miles from the Size
drop-down menu and assign 1 for both X Span and Y Span ⇒ Click
Next twice ⇒ Click Finish.
Create and Configure the Network
Initialize the Network:
1. The Object Palette dialog box should be now on the top of your project
space. If it is not there, open it by clicking . Make sure that the
internet_toolbox is selected from the pull-down menu on the object
palette.
2. Add to the project workspace the following objects from the palette:
Application Config, Profile Config, and a subnet.
a. To add an object from a palette, click its icon in the object palette
⇒ Move your mouse to the workspace ⇒ Left-click to place
the object. Right-click when finished. The workspace should
contain the following three objects:
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Profile Config describes the
Application Config activity patterns of a user or
is used to specify group of users in terms of the
applications that will applications used over a
be used to configure period of time. You must define
users profiles. the applications using
the Application Config
object before using this object.
3. Close the Object Palette dialog box and save your project.
Configure the Services:
1. Right-click on the Application Config node ⇒ Edit Attributes ⇒
Change the name attribute to Applications ⇒ Change the Application
Definitions attribute to Default ⇒ Click OK.
2. Right-click on the Profile Config node ⇒ Edit Attributes ⇒ Change
the name attribute to Profiles ⇒ Change the Profile Configuration
attribute to Sample Profiles ⇒ Click OK.
Sample Profiles provides patterns of applications employed by users
such as engineers, researchers, salespeople, and multimedia users.
Configure a Subnet:
1. Right-click on the subnet node ⇒ Set Name ⇒ Change the name
attribute to
Engineering and click OK.
2. Double-click on the Engineering node. You get an empty workspace,
indicating that the subnet contains no objects.
3. Open the object palette and make sure it is still set to
internet_toolbox.
4. Add the following items to the subnet workspace: 10BaseT_ LAN,
ethernet16_switch, and a 10BaseT_link to connect the LAN with
the Switch ⇒ Close the palette.
5. Right-click on the 10BaseT_LAN node ⇒ Edit Attributes ⇒
Change the name attribute to LAN ⇒ Expand LAN ⇒ Observe
that the Number of Workstations attribute has a value of 10 ⇒
Expand Application ⇒ Expand Application: Supported
Profiles ⇒ Set the number of rows to 1 ⇒ Expand None ⇒ Set
the Profile Name to Engineer.
Note: Engineer is one of the “sample” profiles
provided within the Profile Config object.
7. Click OK.
The object we just created is equivalent to a
10-workstation star topology LAN. The traffic
generated from the users of this LAN resembles
that generated by “engineers.”
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8. Rename the ethernet16 Switch to Switch.
9. The subnet should look like the shown one.
10. Save your project.
Configure All Departments:
1. Now you have completed the configuration of the Engineering
department subnet. To go back to the main project space, click the Go
to the Parent Subnet button.
The subnets of the other departments in the company should be
similar to the engineering one except for the supported profiles.
2. Make three copies of the Engineering subnet we just created: Click
on the Engineering node ⇒ From the Edit menu, select Copy ⇒
From the Edit menu, select Paste three times, placing the subnet in
the workspace after each, to create the new subnets.
3. Rename (right-click on the subnet and select Set Name) and arrange the
subnets as shown below:
4. Double-click the Research node ⇒ Edit the attributes of its
LAN ⇒ Edit the value of the Application: Supported Profiles
attribute ⇒ Change the value of the Profile Name from
Engineer to Researcher ⇒ Click OK ⇒ Go to the parent
subnet by clicking the button.
5. Repeat step 4 with the Sales node and assign to its Profile Name
the profile Sales Person.
6. Repeat step 4 with the E-Commerce node and assign to its Profile
Name the profile E-commerce Customer.
7. Save your project.
Configure the Servers:
Now we need to implement a subnet that contains the servers. The servers
have to support the applications defined in the profiles we deployed. You
can double-check those applications by editing the attributes of our Profile
node. Inspect each row under the Applications hierarchy, which in turn,
is under the Profile Configuration hierarchy. You will see that we need
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servers that support the following applications: Web browsing, Email, Telnet,
File Transfer, Database, and File Print.
1. Open the Object Palette and add a new subnet ⇒ Rename
the new subnet to Servers ⇒ Double-click the Servers node to
enter its workspace.
2. From the Object Palette, add three ethernet_servers, one
ethernet16_switch, and three 10BaseT links to connect the servers
with the switch.
3. Close the Object Palette.
4. Rename the servers and the switch as follows:
5. Right-click on each one of the above servers and Edit the value of the
Application: Supported Services attribute under Application.
i. For the Web Server add 4 rows to support the following services:
Web Browsing (Light HTTP1.1), Web Browsing (Heavy
HTTP1.1), Email (Light), and Telnet Session (Light).
ii. For the File Server add two rows to support the following
services: File Transfer (Light) and File Print (Light).
iii. For the Database Server add one row to support the following
service: Database Access (Light).
6. Go back to the project space by clicking the Go to the Parent Subnet by
clicking the button
7. Save your project.
Connect the Subnets:
Now all subnets are ready to be connected together.
1. Open the Object Palette and add four 100BaseT links to connect
the subnets of the departments to the Servers subnet.
As you create each link, make sure that it is configured to connect the
“switches” in both subnets to each other. Do this by choosing them
from the drop-down menus as follows:
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2. Close the Object Palette.
3. Now your network should resemble the following one:
4. Save your project.
Duplicate the Scenario
In the network we just created we assumed that there is no background
traffic already in the links. In real networks, the links usually have some
existing background traffic. We will create a duplicate of the SimpleNetwork
scenario but with background utilization in the 100BaseT links.
1. Select Duplicate Scenario from the Scenarios menu and give it the
name BusyNetwork ⇒ Click OK.
2. Select all the 100BaseT links simultaneously (click on all of them while
holding the Shift key) ⇒ Right-click on anyone of them ⇒ Edit
Attributes ⇒ Check the Apply Changes to Selected Objects
check box.
3. Expand the hierarchy of the Traffic Information attribute ⇒ Click on
the value of
Number of Rows and assign 1 ⇒ Click enter.
4. Expand the hierarchy of the Row 0 attribute ⇒ Expand the
hierarchy of the 2 Campus Network.*** attribute ⇒ Click on the
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value of Traffic Load of the first and choose 1 ⇒ Click enter.
Link utilization is
the percentage of
the used link
bandwidth.
We now wish to add a background utilization of 99%. That means that we
want the Link Load (bps) to be 99000000 bps and since our simulation
will last 30 minutes we will do the following:
5. Click OK.
6. Save your project.
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Choose the Statistics
To test the performance of our network we will collect one of the many
available statistics as follows:
1 . In each scenario, right-click anywhere in the project workspace and
select
Choose Individual DES Statistics from the pop-up menu.
2 . In the Choose Results dialog box, choose the following statistic:
Page Response Time
is the required time to
retrieve the entire
page.
3 . Click OK.
Configure and Run the Simulation
Here we need to configure the duration of the simulation:
1. Click on the Configure/Run Simulation button
2. Set the duration to be 30.0 minutes.
3. Press Run. Repeat for both simulations.
View the Results
To view and analyze the results:
1. Select Compare Results from Results in the DES menu.
2. Change the drop-down menu in the lower-right part of the Compare
Results dialog box from As Is to time_average, as shown.
3. From the Results for drop-down menu, select Current Project.
4. Check SimpleNetwork and BusyNetwork.
5. Expand Global Statistics ⇒ expand HTTP.
6. Select the Page Response Time (seconds) statistic and click Show.
Questions
1) Analyze the result we obtained regarding the HTTP page response time. Collect
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four other statistics, of your choice, and rerun the simulation of the Simple and the
Busy network scenarios. Get the graphs that compare the collected statistics.
Comment on these results.
2) In the BusyNetwork scenario, study the utilization% of the CPUs in the servers
(Right-click on each server and select Choose Individual Statistics ⇒ CPU
⇒ Utilization).
3) Create a new scenario as a duplicate of the BusyNetwork scenario. Name the
new scenario Q3_OneServer. Replace the three servers with only one server that
supports all required services. Study the utilization% of that server’s CPU.
Compare this utilization with the three CPU utilizations you obtained in the previous
question.
4) Create a new scenario as a duplicate of the BusyNetwork scenario. Name the
new scenario Q4_FasterNetwork. In the Q4_FasterNetwork scenario, replace all
100BaseT links in the network with 10Gbps Ethernet links and replace all
10BaseT links with 100BaseT links. Study how increasing the bandwidth of the
links affects the performance of the network in the new scenario (e.g., compare
the HTTP page response time in the new scenario with that of the BusyNetwork).
