OPNET SP GURU TRANSPORT PLANNER

OPNETSPGURU

TRANSPORTPLANNER

GRADUATE PROJECT WAN/ LAN PLANNIG

AND DESIGN

ROHIT KARHU DATE 04/29/2013

TABLE OF CONTENTS

1. INTRODUCTION ............................................................. 3

2. SCENARIO'S ................................................................... 4

3. DESIGN .......................................................................... 5

4. TOPOLOGIES (UNPROTECTED) ...................................... 6

5. TOPOLOGIES (PROTECTED) ......................................... 42

6. SCENARIO COMPARISON TOOL .................................. 55

7. CONCLUSION ............................................................... 60

8. REFERENCES ................................................................ 60

1. INTRODUCTION

"OPNET was Alain Cohen's (co‐founder and current CTO & President) graduate project

for a networking course while he was at MIT. OPNET stood for Optimized Network Engineering

Tools. Alain, along with brother Marc (co‐founder and current CEO & Chairman) and classmate

Steven Baraniuk, decided to commercialize the software[1]". The goal of this graduate project is

to explore and learn OPNET SP Guru Transport Planner which is used to simulate optical

networks. This report shows design and simulation of different topologies using OPNET and

how OPNET is used to compare the performance characteristics of optical network, thereby one

can figure out most effective or least costly network. Now to learn this tool in great detail,

various topologies are designed and simulated and compared / analyzed and for the purpose of

this exercise following example is considered:‐

Bank of America wants to expand their business internationally as well as they want

major cities within United States to be connected to international cities and form a network.

They have approached Time Warner for the solution and proposed that they should design

various network topologies and respective performance of each topology so that it will be

easier for Bank of America to decide most effective network. Now, the network engineer from

Time Warner will make use of OPNET to design the Network and will show the results of

designed networks to the Bank based on the results he will get from OPNET. The following cities

needs to be connected:‐

Cities within USA:‐

a) Los Angeles

b) Dallas

c) Miami

d) Minneapolis

e) Denver

f) Raleigh

International Cities:‐

a) Mexico City

b) Havana

c) Vancouver

d) Ottawa

2. SCENARIO'S

Considering main goal of this graduate project, there are two scenario's defined in this

project:‐

Unprotected

Protected (1 + 1 Path Protection)

And in each category various topologies are defined i.e. In Unprotected, Star, Multilink

and Fully Meshed topologies are designed. In Protected, Multilink i.e. Hybrid topology and

Totally Meshed topology. The topologies which are considered are as below:‐

I. Star Topology

II. Totally Meshed Topology

III. Multilink Topology

3. DESIGN

Once the topology is designed in OPNET, following network properties and other

aspects are defined for each topology. SONET systems and optical transparency in Opaque

mode is considered while designing each topology. All distances are in miles :‐

3.1 Topology

A) Network Properties

I) Network Topology

II) Link Design

III) Link Threshold

IV) Delay Settings

V) Network Availability

B) Traffic

I) Traffic Matrix

II) Traffic Dimensioning

III) Routing Results

IV) Traffic Variation

C) Network Cost

I) Node and Link Cost

D) Web Reports

E) Failure Analysis

I) Link failure

II) Node failure

3.2 Scenario Comparison

A) Between Unprotected and Protected Totally meshed topologies

B) Between Unprotected and Protected Multilink topologies

C) Between all topologies

4. TOPOLOGIES (UNPROTECTED)

For the purpose of this project following topologies are designed. All are designed in

unprotected mode:‐

4.1 Star Topology

For star topology, Dallas is selected as central node.

4.1.1 Network Diagram

4.1.2 Topology Info

The topology info states that there are total 10 nodes, 9 links and connectivity is 20%

and some aspects like link capacity and cable length info can be learnt from the screen above.

4.1.3 Network Availability

The network availability is set to 99.999% for cables, line systems and nodes, including

optical amplifiers, regenerators, patch panel and OTS, OMS nodes.

4.1.4 Delay Settings

Global delay settings is set to 0.005 ms/mile.

4.1.5 Network Properties

SONET technology is selected. For OCH layer Opaque mode is chosen. The default

bit rate for DCL link is set to OC‐192 since its common bit rate in use. Network

properties are set as following screen:‐

4.1.6 Link Usage Threshold

The link usage threshold is set to 50% considering 50% link utilization criteria, the most

important aspect while designing links for a network.

4.1.7 Traffic Matrix

While designing traffic matrix random traffic utility of OPNET is selected and traffic is generated

from 15 to 50.

4.1.8 Link Design

Please see below the details of link design results, It gives information about number of

regenerators used, OA sites added and cable length per link.

4.1.9 Traffic Dimensioning

Since topology is designed for unprotected network, Unprotected is selected. Optical

node & link utilization is set to 50%. The settings for dimensioning the network are as shown &

selecting generate web report creates a web report and displays results of dimensioning:‐

4.1.10 Routing Results

We got link utilization at OCH layer as 48.62%. The mean hop is 1.8

4.1.11 Traffic Variations

Under traffic variation, 20% increase in traffic is added and analyzed the results. For star

topology link utilization is increased from 48.6% to 49.9% but being a star topology not 100%

but 85.8% traffic is routed.

4.1.12 Network Cost

Network cost is calculated separately for link, node and total cost of the network. Also

bill report generator utility is also tested which gives very detailed information about each and

every aspect of the network. Please refer to the screens below (To avoid redundancy all screens

related to cost are not posted):‐

4.1.13 Link Failure Analysis

For link failure analysis, two links are failed between Dallas to Minneapolis and Dallas to

Los Angeles and the number of wavelengths that are failed are calculated. For this scenario out

of 1513, 482 wavelengths are lost i.e. 31.85% and none are recovered as the network is

unprotected. Please refer the screens below:‐

4.1.14 Node Failure Analysis

Especially for node analysis of star topology two types of node failures are

carried out 1) Central node failure 2) Other nodes failure. Similar to link failure the

percentage loss for case 1 is 100%, as the traffic cant flow if the central node fails and

for second case wavelength loss is 34.76 (526 are lost out of 1513). Please refer to the

screenshots below. Also a screenshot of network topology at OCH layer view is included

which represent optical line systems and cross connects, as it shows failed lines in

orange color.

1) Mid node failure:‐

2) Other Node Failure ( Ottawa and Vancouver)

OCH Layer View

4.2 Totally Meshed Topology

In this topology all the nodes are connected to each other. There are total 10

sites in this network which means the total number of links present are 10*9 / 2 =45

links. In this topology we'll see the network settings, traffic parameters and failure

analysis of links as well as of nodes.


The network diagram for totally meshed network is shown below, which shows

how each and every node is connected to each other, meaning there are 9 links from

each and every node of the network.

4.2.2 Topology Info

The topology info states that there are total 10 nodes, 45 links and connectivity is 100% (due to

totally meshed network) and some aspects like link capacity and cable length info can be learnt

from the screen below.




SONET technology is selected. For OCH layer Opaque mode is chosen.

Regenerate via DXS is checked. The default bit rate for DCL link is set to OC‐192 since its

common bit rate in use. Network properties are set as following screen


The link usage threshold is set to 50% considering 50% link utilization criteria,

the most important aspect while designing links for a network.


While designing traffic matrix random traffic utility of OPNET is selected and traffic is

generated from 15 to 50.

4.2.8 Link Design

Please see below the details of link design results, It gives related information

about number of regenerators used, OA sites added and cable length per link. These are

the settings used for designing the link, OTS links are chosen and regeneration locations

is set to Mid Span.




selecting generate web report creates a web report and displays results of dimensioning‐


Please see below screen shot of routing results. We got link utilization at OCH layer as 48.33%.

The mean hop is 1.1.


Under traffic variation, 20% increase in traffic is added and analyzed the results. For totally

meshed topology link utilization is increased from 48.3% to 50% and 84.7% traffic is routed.

4.2.12 Network Cost



every aspect of the network. Please refer to the screens below:‐


For link failure analysis, six links are failed as shown in topology below and the number

of wavelengths that are failed are calculated. For this scenario out of 1562, 257 wavelengths

are lost i.e. 16.45% and none are recovered as the network is unprotected. Please refer the

screens below:‐


Similar to link failure 3 nodes are failed and out of 1562, 973 wavelengths are lost

(62.29% loss) and none are recovered due to unprotected topology. Please refer to the

screenshots below. Also a screenshot of network topology at OCH layer view is included which

represent optical line systems and cross connects, it shows failed lines in orange color. Lots of

links are failed as from each node there are 9 links that go to other sites.

OCH Layer view

4.3 Multilink Topology

Multilink network is nothing but a hybrid network showing characteristics of two or

more networks. The following topology is composed of ring and star topology. In this topology

we'll first define the network parameters, define traffic on links, calculating cost and both node

and link analysis is performed.


The network diagram for Multilink network is shown below. It consists of 10 sites out of which 8

sites form a ring from outer side and two sites inside the ring is forming a star network with

adjacent sites.

4.3.2 Topology Info

The topology info states that there are total 10 nodes, 19 links and connectivity is 42%

(due to totally meshed network) and some aspects like link capacity and cable length info can

be learnt from the screen below:‐




SONET technology is selected. For OCH layer Opaque mode is chosen. Regenerate via

DXS is checked. The default bit rate for DCL link is set to OC‐192 since its common bit rate in

use. Network properties are set as following screen


The link usage threshold is set to 50% considering 50% link utilization criteria, the most

important aspect while designing links for a network.




4.3.8 Link Design

Please see below the details of link design results, It gives information about number of

regenerators used, OA sites added and cable length per link.




selecting generate web report creates a web report and displays results of dimensioning.


We got link utilization at OCH layer as 48.75%. The mean hop is 1.7



topology link utilization is increased from 48.8% to 49.9% and 85.9% traffic is routed.

4.3.12 Network Cost





For link failure analysis, three links are failed as shown in topology below and the

number of wavelengths that are failed are calculated. For this scenario out of 1418, 380

wavelengths are lost i.e. 26.79% and none are recovered as the network is unprotected. Please

refer the screens below:‐



(68.05% loss) and none are recovered due to unprotected topology. Please refer to the

screenshots below. Also a screenshot of network topology at OCH layer view is included which

represent optical line systems and cross connects, it shows failed lines in orange color, so it

becomes easy to analyze.

OCH Layer View

5. TOPOLOGIES (PROTECTED)

For protected scenario two topologies are considered:‐

1) Multilink network

2) Fully Meshed network

This topology is designed in the similar fashion as It's been done for unprotected scenario, the

only difference is while dimensioning the traffic 1+1 protection path is selected. Now some of

the network parameter's settings done while designing these topologies are similar to the

topologies designed in unprotected multilink network. So please refer to section 4.3 for

following network parameters:‐

Network Diagram, Topology Info, Network Availability, Delay Settings, Network Properties, Link

Usage Threshold.

We will show only those aspects of network which are different than unprotected

network and those are as follows:‐

5.1 Multilink Topology





Since topology is designed for protected network, 1+1 path protection is selected.

Optical node & link utilization is set to 50%. The settings for dimensioning the network are as

shown & selecting generate web report creates a web report and displays results of

dimensioning:‐


We got link utilization at OCH layer as 49.12%. The mean hop is 1.7 & in protecting mode its 2.4

5.1.4 Ring Browser

This topology is designed taking into consideration the advantages of both star and ring

topology and therefore the advantage we get is if a link fails there always will be another link

which can take care of traffic. This is because there are small rings formed inside the network

and using ring browser we can analyze that. Please refer the screen shot below:‐


Under traffic variation, 20% increase in traffic is added and analyzed the results.

For star topology link utilization is increased from 49.1% to 49.5% And 84% traffic is

routed.

5.1.6 Network Cost





For link failure analysis, three links are failed as shown in topology below and the

number of wavelengths that are failed are calculated. For this scenario out of 1493, 86

wavelengths are lost and 253 are recovered due to 1+1 Path restoration so the loss is only

5.76% which is much less than the loss occurred in unprotected network. Please refer the

screens below:‐



(49.63% loss) and 283 are recovered due to protected topology. Please refer to the screenshots

below.

5.2 Totally Meshed Topology

This topology is designed in the similar fashion as It's been done for unprotected scenario, the

only difference is while dimensioning the traffic 1+1 protection path is selected. Now some of

the network parameter's settings done while designing these topologies are similar to the

topology designed in unprotected totally meshed network. So please refer to section 4.2 for

following network parameters:‐

Network Diagram, Topology Info, Network Availability, Delay Settings, Network Properties, Link

Usage Threshold. We will show only those aspects of network which are different than

unprotected network and those are as follows:‐





Since topology is designed for protected network, 1+1 path protection is selected.

Optical node & link utilization is set to 50%. The settings for dimensioning the network are as

shown & selecting generate web report creates a web report and displays results of

dimensioning:‐


We got link utilization at OCH layer as 49.26%. The mean hop is 1 and in protecting mode its 2.



topology link utilization is increased from 49.3% to 49.5% 83.8% traffic is routed.

5.2.5 Network Cost





For link failure analysis, five links are failed as shown in topology below and the number

of wavelengths that are failed are calculated. For this scenario out of 1533, 66 wavelengths are

lost and 143 are recovered due to 1+1 Path restoration so the loss is only 4.305% which is

much less than the loss occurred in unprotected network. Please refer the screens below:‐



(35.74% loss) and 8 are recovered due to protected topology. Please refer to the screenshots

below.

Also a screenshot of network topology at OCH layer view is included which represent

optical line systems and cross connects, it shows failed lines in orange color, so it becomes easy

to analyze.

6. SCENARIO COMPARISON TOOL

Scenario comparison tool is used to compare scenarios of user's choice. Once the user

Inputs the scenario he wishes to compare, a graphical representation of those scenarios is

shown in terms of bar graph. This is a very simple to use and understand tool and gives clear

idea about the network performance parameters and therefore it becomes easy to pick most

effective network.

For the purpose of this project we'll show comparison between protected and

unprotected network of each topology and in at the last we will have comparison of all the

topologies we have covered so far.

6.1) Comparison between unprotected and protected Totally meshed network

We will cover cost comparison in terms of link cost, node cost and link cost. For

performance we'll see Utilization chart at OCH level. Please refer to relevant screens below:‐

From these figures we can easily figure out the cost of each and every small aspects and

equipments that are involved in the network cost and hence becomes easy to improvise if

reduced cost network needs to be designed. For performance it's clear that protected totally

meshed network will stand out as utilization as well as few other aspects are higher that

unprotected totally meshed topology.

6.2) Comparison between unprotected and protected Multilink network

We will cover cost comparison in terms of link cost, node cost and link cost. For

performance we'll see Utilization chart at OCH level. Please refer to relevant screens below:‐

From these figures we can easily figure out the cost of each and every small aspects and

equipments that are involved in the network cost and hence becomes easy to improvise if

reduced cost network needs to be designed. For performance it's clear that protected multilink

network will stand out as utilization as well as few other aspects are higher that unprotected

multilink network.

6.3) Comparison between all networks covered so far

For comparison between all networks we will cover the network cost of all then we'll

see number of links, connectivity, utilization, capacity and capacity*distance‐ protected

parameter for all topologies. Please refer to the corresponding screenshots below:‐

From the above comparison it can be easily seen that, every network profile have its

own advantages and disadvantages. e.g. Connectivity and utilization for totally meshed

protected network is good but it's the most expensive network amongst all. Multilink

unprotected network is low but so is its connectivity. The only profile which stands has better

network performance characteristics and also is cost effective is Multilink Protected network.

7. CONCLUSION

From this graduate project, we designed different topologies and learnt how to set the

network parameters, define traffic and calculate the cost and performance parameters that

profile. We increased the traffic by 20% to see what it affects on network performance and

OPNET is a great tool to do failure analysis of the network which gives a brief idea of what will

be the consequences in case of node or link failure and that's one great advantage of using

OPNET.

After designing 5 different topologies we learnt that every topology has its own

advantages and disadvantages. unprotected networks sure are cheap but it decreases the

reliability of the network, whereas protected i.e. 1+1 path protected networks sure are better

than others in terms of reliability, link utilization and capacity but that too comes with a great

price. However in the failure analysis is performed for protected networks it is clear that due to

an additional path ( 1+1 path restoration) not much wavelengths were affected and few of

them were able to recover also so the % loss of wavelengths in protected networks was much

more less than that of unprotected networks.

The comparison tool within the OPNET is also a great way of learning and comparing the

network parameters and we conclude that Time Warner should suggest Multilink Protected

network to Bank of America as it turned out to be most effective network amongst all as it gives

great network performance in exchange of a reasonable cost.

8. REFERENCES

1) http://en.wikipedia.org/wiki/OPNET

2) http://www.cs.tut.fi/kurssit/TLT‐2707/lecture12.pdf

3) http://www.rit.edu/cast/ectet/Opnet/OpnetProjects.html

OPNET SP GURU TRANSPORT PLANNER

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