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MSCIT Practicum Paper

Ranjan Kaparti

Professor Dan Likarish


Chapter 1: Introduction

Chapter 2: Solutions

Chapter 3: OPNET IT Guru Overview Page

Chapter 4: OPNET IT Guru for Education

Chapter 5: Multimedia Quickstart and Labs


Chapter 1: Introduction: The Problem

Computer networks are ubiquitous and such a state of affairs
creates demand for qualified personnel who can work with
networks. Unsurprisingly many institutions of learning (high-
school and higher learning) are teaching the relevant set of
networking technologies. Many are interested in creating new
programs and curricula with networking content.

The question arises as to how best to teach this material.
Michael Dixon, Tanya McGill, and Johann Karlsson point out that
many of the relevant concepts are difficult to really grasp in a
purely theoretical way. Lectures alone do not accomplish the
trick. And practical assignments - labs - must move beyond mere
programming assignments. Though writing say, a custom
communications protocol, is a good exercise, it falls short if
the goal is to teach the big picture of network communications
and associated high-level decision making and analysis. (Dixon,
McGill and Karlsson 71)

The nature of the technology itself is such that it is difficult
to get “hands on” with it from the point of view making the
technology available for classroom use. There is the issue of
expense. Many high schools for instance may not have the
resources to build an appropriate lab with all relevant hardware
and software. Furthermore real world networks may span not

merely a lab or two but rather entire buildings or even multiple
global locations. Noel Davis, Scot Ransbottom and Drew Hamilton
point out that:
Most networks are built to accommodate the needs of a single
organization or group. Internetworking is a technology that
accommodates multiple, diverse, underlying hardware by providing
the means of interconnecting heterogeneous networks.
Comparatively few individuals, academic institutions or
corporations have networks exclusively dedicated for student use
and experimentation. Prudent administrators limit student or
general user access to operational networks. (Davis, Ransbottom
and Hamilton 104)

Davis et al make some good points here. Even if there is a
network designated for student use it is rare that the network’s
sole purpose is to support the networking curriculum. Students
may gain valuable experience managing a network which is in
deployment (for general uses); however such experience has
limitations. For instance suppose a school decides to run the
Windows family of servers on their networks and the school
designates a lab for networking students’ use. Students may
learn a lot about Windows servers and associated technologies but
they will not obtain hands on training with Linux based
technologies. Even if one sets aside the worry about not being
able to learn the relevant range of technologies, students will
likely not be allowed to change settings and reconfigure things
to any significant extent in the Windows based network.

The bottom line seems to be that networking curricula face the
following dilemma: on the one hand it is expensive to set up a
networking lab and on the other, even if one makes that

investment, such labs have significant limitations from the point
of view of pedagogy. One cannot hope to cover the diversity of
technologies and configurations and furthermore large scale
networks cannot be built specifically for student use – the costs
are surely too prohibitive.

This problem of making available appropriate hands on computer
networking training is even more acute if one considers distance
education. In distance education (whether synchronous online,
asynchronous online, video based) students are in disparate
locations. It would be impossible to collect them together for
the sake of hands-on training – unless one mandates that for
brief periods of time – in which case it no longer would be
really purely distance learning. Indeed according to Brian
Cameron and K. Wijekumar:
Computer networking, as defined as the interconnection of
computers and computing equipment using either wires or radio
waves over small or large geographic areas (White, 1994), has
long been regarded as one of the more difficult technology-
related subjects to teach. Historically, this type of course was
thought to require much hands-on interaction with the instructor
and was not viewed as a good candidate for an online course.
(Cameron and Wijekumar, 117)

It would be hard to imagine serious educational institutions
creating mini networking labs with actual hardware in every
distance learning student home or workplace. The costs, even if
partially to be passed on to the students, are simply too high.

Chapter 2: Solutions

Even though the picture prima facie appears bleak, there are some
viable solutions that would address not only the needs of
traditional but also those of non-traditional (distance)
networking students. The main solution of interest here is
network modeling and simulation software. In particular OPNET
IT Guru is going to be the focus.

Appropriate network modeling and simulation software could be
used to model networks down and up to whatever scale or detail
that is necessary. Students learn by creating virtual networks
and devices of all kinds and are not limited by network hardware
availability concerns. There is the prospect that distance
students can participate fully – all it would take is student
access to a workstation to run the software. The student’s home
computer itself would likely fit the bill.

Indeed studies have already been done that show significantly
improved learning outcomes in networking technology distance
students who used network modeling and simulation software and
those distance students who did not. Cameron and Wijekumar
claim that network simulation software increases student
motivation in online courses. One of the biggest problems in
distance education (according to them) is lack of sustained
student motivation and involvement. Network simulation software

gives students something tangible to do – a feeling of having
accomplishing something real and hands on and thus lessens drop
out rates. (Cameron and Wijekumar, 116f)

Cameron and Wijekumar actually conducted a study with an online
networking course for undergraduates (Cameron and Wijekumar,
118). One course used “static” network design package -
Microsoft Visio - for design assignments while the other course
used network simulation and modeling software for all their work.
It was not OPNET IT Guru but rather one made by NetCracker
Corporation. Nonetheless NetCracker’s software is dynamic as
well – permitting a range of modeling, design and simulation
functionality (LAN, MAN, WAN). It was found that students with
NetCracker software had a lower drop out rate, and rated their
learning to be much higher. They spent more time on their
assignments and explored “what if” scenarios. The ones with
Microsoft Visio felt that they did not quite know if their
network designs really worked or not before submitting them to
the instructor.

Cameron and Wijekumar further point to a number of studies which
collectively suggest the following good things about simulation
and modeling as a general pedagogical technique:

“Simulations enable knowledge application through
multidimensional problem solving.” (Cameron and Wijekumar,

“Simulations have been shown to improve knowledge
transfer(Cameron and Wijekumar, 119)
“Simulations have been shown to increase understanding
of abstract concepts.” (Cameron and Wijekumar, 119)
“Simulations and modeling can help instructors target
students at multiple levels of learning.” (Cameron and
Wijekumar, 119)
“Simulations have the potential to improve students’
abilities with complex and evolving problem solving
situations.” (Cameron and Wijekumar, 119)

It seems therefore to be almost a “no-brainer” to incorporate
network simulation and modeling software into the curriculum.
The advantages in terms of cost, student involvement and learning
outcomes, utility in distance learning, the ability to give
practical experiences about technologies of a wide range and/or
that are simply too expensive are so impressive and great that it
makes very little sense to reject this solution.

In the market there appear to be two major options for networking
and simulation software. Boson’s NetSim and OPNET’s IT Guru are
mentioned widely in the literature. The latter appears to be more
widely adopted in academy. The former seems to target the
Cisco’s line of networking examination and prep markets and not
necessarily networking in general (Boson Corporation, “Boson
NetSim: Education by Simulation”). In contrast IT Guru is
comprehensive and technology neutral in its capabilities and
versatility. However that fact by itself ought not to count
against NetSim. It may be that both pieces of software have
worthwhile roles to play in the curriculum. For the sake of
focus OPNET’s IT Guru will be pursued in depth here.

Chapter 3: OPNET IT Guru: Overview

IT Guru enables one to create a virtual network consisting of
relevant hardware, protocols, and application software (OPNET
Corporation, Slide 2 of “IT Guru QuickStart”, PowerPoint
Presentation, 2004). This network is a purely software entity
that can run on an individual workstation. Routers, switches,
web servers – almost anything found in real networks – can be
duplicated in an IT Guru virtual network. It can be scaled from
just a network of two workstations to one representing tens of
thousands running in a WAN.

Once a virtual network is created it can be manipulated in
various ways – for instance routers can be added or subtracted,
protocols switched around or altered, web servers added or
discarded – any permutation imaginable. The effects of various
alterations and diverse configurations can then be usefully and
quantifiably examined and analyzed. Importantly IT Guru allows
one to study and gather useful statistics about a virtual network
built from it. IT Guru permits not only the building of a
virtual network in software but also provides tools for
dynamically investigating the thus engendered network. (OPNET
Corporation, Slide 17 of “IT Guru QuickStart”, PowerPoint
Presentation, 2004).

The following high level architectural rendering of IT Guru is an
ideal place to get started. It shows IT Guru and its major

IT Guru Workflow – Inputs and Outputs
Flow Analysis:
Visualize and study steady-state data flow, capacity planning, failure analysis – extensive
Operational configuration validation – protocol-specific and policy-based

Simulates precise protocol effects for capacity planning, tuning protocol behavior, response
time engineering, technology migration, QoS, etc.
Application performance troubleshooting: visualize performance, diagnose problems, explore

Steady-state Throughput/Util;
100+ Reports; Path/Failure
Topology, and
Configuration validation
Graphs, web reports, charts, for
all time-varying network
performance metrics (e.g., app
response time, queue depths,
Virtual Network
Application Visualization,
Diagnosis, Analysis, Protocol
Application Trace
Sniffer, OPNET Application Capture Agent, etc.

Source: OPNET Corporation, Slide 377 of “IT Guru QuickStart”,
PowerPoint Presentation, 2004

The virtual network environment represents a network. It can
have a slew of components in every salient category. Opnet
defines a topology as a “collection of links, nodes and
configuration.” (OPNET Corporation, Slide 203 of “IT Guru
QuickStart”, PowerPoint Presentation, 2004) By “nodes” Opnet
means to include networking hardware of all kinds (routers,
workstations, switches, hubs etc). By “links” the underlying
connectivity technology (Ethernet, ATM, etc) and relevant
characteristics (latency, bandwidth) are meant. In