Data Communication Network Design for uSoft.com Head Office LAN

Desklib provides past papers and solved assignments for students. This project details the design of a new LAN for uSoft.com.

SASANK CHALASANI - 23154786
ASSIGNMENT -3
DATA COMMUNICATION
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Contents
1. INTRODUCTION...................................................................................................................................3
2. REQUIREMENT ANALYSIS....................................................................................................................3
3. NETWORK DESIGN...............................................................................................................................5
3.1 SECURITY...........................................................................................................................................5
3.2 WIRELESS...........................................................................................................................................5
3.3 VIRTUAL LAN......................................................................................................................................6
4. IP ADDRESS ALLOCATION PLAN...........................................................................................................6
5. LOGICAL DIAGRAM............................................................................................................................10
6. PHYSICAL NETWORK TOPOLOGY...................................................................................................11
7. CONCLUSION.....................................................................................................................................12
REFERENCES..............................................................................................................................................13
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1. INTRODUCTION
Every business envisages the growth in demand for its services and an increase in revenue to
denote the realization of projected expectations. When business growth increases, technical
capacity must be expanded to support the surge in operations. For uSoft.com the recent
changes require a redesign of the LAN at the head office which handles the bulk of operations
and oversees the branch offices spread across the gold coast region. The office LAN supports all
business and technical operations and defines her ability to continually deliver value to
customers.
The redesign of the network focuses on meeting a varied number of business and technical
goals. It begins with an analysis of the user requirements for a company’s HQ local area
network. Preceding this analysis is the logical network design for the LAN. The logical design will
provide the framework for building other aspects of the design process. Finally, the IP address
plan for the HQ LAN will be created for the proposed design and the network diagrams for will
be presented to validate the concepts of the design process.
2. REQUIREMENT ANALYSIS
The process of engineering user requirements begins with analyzing the business and technical
goals of the network design as requested by the client. Business requirements are profit-driven
while technical requirements evaluate capacity for service delivery. The business requirements
highlighted by the client begin with improving communications for users, provision of wireless
access and voice over IP (VoIP) services. Communications between different nodes on the
network can be impacted by the paths traffic transverses from source to destination. A negative
outcome of a bad design can result in suboptimal routing which is a scenario where traffic takes
a longer route towards the destination. Mobility enables users to overcome the challenges of
being restricted to an enclosed workspace to maintain connectivity to network resources. The
final business requirements focus on the integration of VoIP services to the new infrastructure.
VoIP services differ from traditional data networks because of the stringent bandwidth
requirements that characterize its operations. For the current design, all of these business goals
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will be accounted for using best practice concepts and analogies when defining the technical
component of the network.
Technical requirements are driven by business concerns raised by the client and discussed in
the preceding paragraph of the user requirements. To analyze the technical needs that the new
proposed design must provide, we begin by evaluating the benefit of proposing a scalable
network architecture. Scalability anticipates future growth of the network and incorporates the
design principles and technologies to accommodate this growth. As the network grows,
increased usage remains invisible to users because the network has the capacity to manage all
resources. An emerging type of network user that the network must carter for are remote
workers. The company policy and business landscape require certain users to be able to access
the network from an external end host device. To provide external access, remote access virtual
private network (VPN) solution will be configured on the network security gateways. A VPN
secures connections over public infrastructures and protects data integrity. An additional
technical requirement is focused on ensuring that the performance of the new design does not
fall below expectations. An evidence of optimum performance is when users can access the
various services without experiencing delay or lags. Concluding the technical requirements are
3 additional design goal, the first is the security of the network. Designing a secure network is
an essential goal that envelopes every other aspect of the technical requirement. The new
network creates a layer of security that protects network resources and users. The foundational
concept of the current design segments the network into logical groupings for ease of
administration and configuration. This enhances the flexibility of the design and also support a
scalable approach to grow the number of users on the network by creating additional user
groups. Finally, the network must be available for all users accessing the network via the
wireless access points. Availability measures uptime of services over a prolonged period of
time. Creating a logical network design with all the technical requirements is what the next
sections build upon. The final network is a validated and dependable solution that can be
deployed at uSoft HQ.
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3. NETWORK DESIGN
A network design consists of two distinct phases, the first is a logical design and the other is
physical design. The purpose of a design is to propose the best architectural model for building
the interconnectivity between the different network components. Choosing the best model for
the current proposed design builds on the analyzed business and technical requirements. It is
also the foundational concept for engineering any network because the model of a network
inhibits the characteristics of the network. Utilizing a well-defined model for uSoft network I will
begin by defining the logical network design for the company’s new network.
3.1 SECURITY
Security has been described as a core goal of the current design for uSoft because of the need
to minimize the risk associated with security incidents that can disrupt business operations. A
best practice design model utilizes a three-tier model to implement security. The tiers can also
be referred to as zones. These are the internet (unsecured zone), a DMZ and the internal
network. The DMZ acts as a buffer between internal host and servers that can be accessed
externally. Traffic between the DMZ and the internal network is unidirectional, permitting
connections initiated by internal host and denying connection request originating from the
DMZ. To implement this model, a firewall will be used to create the segmentation between the
zones. The firewall will also provide traffic filtering, antimalware. Beyond modelling of network
security, the foundational concept that will be used to achieve optimum security involves the
planning and implementation of security policies.
3.2 WIRELESS
A wireless network provides connectivity over radio frequencies channels. Designing a wireless
network for the floor plan provided requires adequate planning in order to provide full
coverage for the area being considered and also minimize the number of access points (AP). A
wireless AP design for the network will segment the floor plan into six equal halves and assign
an AP for each area, a total of 6 AP’s will be used. Security is also a requirement for wireless
network because it can be another access for network attacks. The best wireless security for the
current network is WI-FI protected access (WPA2) using pre-shared keys for authentication of
clients.
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3.3 VIRTUAL LAN
A virtual LAN (VLAN) is a logical segmentation of the network at the data link layer of the OSI
model. This logical segmentation represents multiple broadcast domains and layer 3 IP subnets.
Each network segment represents a group of devices or a group of a host connected to the
network. Devices on the network are unaware of the presence of VLANs because it configured
on the switches. In the design of uSoft network, VLANs will be created for each workgroup or
department and using the unique IP subnet for each department (six VLANs) the network will
be implemented with ease. Communication between VLANs requires a layer 3 device, but for
this design proposal, inter-VLAN routing will be implemented on layer 3 switches.
4. IP ADDRESS ALLOCATION PLAN
IP is important to define a structured model for address allocation. An IPv4 address is a 32-bit
logical address that uniquely identifies each host on the network. An IP address has two parts, a
host portion and a network portion. A subnet mask identifies which portion of the address
belongs to the network and the bits uniquely identifying host devices. Each subnet has a range
of host addresses and includes a broadcast address for communicating with all nodes in that
subnet.
Subnetting is the process of taking a large network address and breaking it into smaller
networks or subnets. These subnets are assigned to different user groups or device groups on
the network. As previously stated, each VLAN is a subnet and this address allocation scheme is
targeted at providing adequate addresses for the logical network segments.
Utilizing the assigned address for the company which is 172.16.1XY.0/22 and ID which is
23154786. The assigned address that will be subnetted is 172.16.123.0/22. To subnet, the
network the variable length subnet mask scheme will be used because it minimizes the wastage
of host address. Beginning with the largest segment I will create a subnet for that number of
host and conclude with the smallest segment or least host segment.
1. SOFTWARE DEVELOPMENT:
The total number of host devices is 10X where X=2, this value is 102.
In this department, each employee has a phone and a PC and there are three servers
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The total number of devices is 207
207 host addresses require 8 host bits, the current network address has 10 host bits.
This leaves 2 bits for the network resulting in 4 new subnets.
These are:
1. 172.16.123.0/24,
2. 172.16.124.0/24,
3. 172.16.125.0/24,
4. 172.16.126.0/24,
The assigned subnet is 172.16.123.0/24 for the software development
Host range: 172.16.123.1 – 172.16.123.255, Gateway address: 172.16.123.1/24
2. SOLUTION DESIGN
The total number of host devices is 9x where x=2. This value is 92 host.
Each user has a PC and a phone and there are 2 servers. This brings the total to 186.
186 host addresses require 8 host bits
The subnet 172.16.124.0/24 will be assigned to the Solution design department.
Host range: 172.16.124.1 – 172.16.124.254, broadcast: 172.16.124.255, Gateway
address: 172.16.124.1
3. CUSTOMER SUPPORT
The total number of host is 6X where x=2, this value is 62.
But each user has a PC and a phone and there is 1 server for this department. The total
number of devices is 125.
125 devices require 7 host bits. Subnetting the network 172.16.125.0/24 into two
networks gives: 172.16.125.0/25 as well as 172.16.125.128/25
The subnet 172.16.125.0/25 will be assigned to customer support.
Host range: 172.16.125.1 -172.16.125.126, Gateway: 172.16.125.1, broadcast:
172.16.125.127
4. SALES
The total number of host devices is 5x where x=2. This value is 52 host.
Each user has a PC and a phone and there is 1 server. This brings the total to 105.
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105 host addresses require 7 host bits
The subnet 172.16.125.128/25 will be assigned to sales.
Host range: 172.16.125.129 – 172.16.125.254, broadcast: 172.16.125.255, Gateway
address: 172.16.125.129
5. FINANCE
The total number of host is 3X where x=2, this value is 32.
But each user has a PC and a phone and there is 1 server for this department. The total
number of devices is 65.
125 devices require 7 host bits. Subnetting the network 172.16.126.0/24 into two
networks gives: 172.16.126.0/25 as well as 172.16.126.128/25
The subnet 172.16.126.0/25 will be assigned to finance.
Host range: 172.16.125.1 -172.16.125.126, Gateway: 172.16.126.1, broadcast:
172.16.126.127.
6. HUMAN RESOURCE
The total number of host devices is 2x where x=2. This value is 22 host.
Each user has a PC and a phone and there is 1 server. This brings the total to 45.
45 devices require 6 host bits, the last available subnet has 126 host address.
Subnetting the network 172.16.126.128/25 into 2 networks gives
172.16.126.128/26 as well as 172.16.126.192/26
Assign the network 172.16.126.128/26 to human resource.
Host range: 172.16.126.129 – 172.16.126.190, Gateway: 172.16.126.129, broadcast
172.16.129.191.
HEAD OFFICE
DEPARTMENT REQUIRE
D HOST
NETWORK
ADDRESS
HOST RANGE
ADDRESS
SUBNET MASK BROADCAST
SOFTWARE
DEVELOPMEN
T DEPT.
207 172.16.123.0/2
4
172.16.123.1 to
172.16.123.254
255.255.255.0 172.16.123.255
SOLUTION
DESIGN DEPT.
186 172.16.124.0/2
4
172.16.124.1 to
172.16.124.254
255.255.255.0 172.16.124.255
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CUSTOMER
SUPPORT
DEPT.
125 172.16.125.0/2
5
172.16.125.1 to
172.16.125.126
255.255.255.1
28
172.16.125.127
SALES DEPT. 105 172.16.125.128
/25
172.16.125.129
to
172.16.125.254
255.255.255.1
28
172.16.125.255
FINANCE
DEPT.
65 172.16.126.0/2
5
172.16.126.1 to
172.16.123.126
255.255.255.1
28
172.16.126.127
HUMAN
RESOURCE
DEPT.
45 172.16.126.128
/26
172.16.126.129 –
172.16.126.190
255.255.255.1
92
172.16.126.191
(Henderson, 2003)
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5. LOGICAL DIAGRAM
A logical network represents the flow of traffic between the nodes on the network. It does not
depict the location of the devices on the network but rather how the devices can be
interconnected to create a network.
Figure 1: logical network topology
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6. PHYSICAL NETWORK TOPOLOGY
A physical network topology shows the location of the cable connections between the hosts on
the network. The physical topology for USoft network is shown below.
Figure 2: Physical topology
(Kenyon, 2002)
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7. CONCLUSION
The redevelopment of the existing LAN has been successfully completed with detailed
topological information for the company’s network. The design began by considering the
technical and business requirements for the client’s new network. This was followed by
network design for logical and physical network components. The IP addressing scheme for the
network provided logical addresses for each host in the departments. To minimize address
wastage the variable length subnet mask scheme was utilized for this purpose. In conclusion,
the new design is an ideal network for the client and can be used to implement the network.
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