Network Redesign Proposal for uSoft: A Comprehensive Solution

Desklib provides past papers and solved assignments for students. This project details a network redesign for uSoft Biomedical.

DATA COMMUNICATION – ASSIGNMENT

SUMMARY
Information technology has become the lifeline of any technologically driven processes. Every
activity of man has an inbuilt IT component that services and delivers the desired outcome. The
challenge of IT-driven businesses is that they must adapt themselves to the dynamic nature of
the technology deployed in any networked environment. As IT evolves a review of the
underlying capacity for continuous service delivery is necessary in order to support the way
businesses operate.
uSoft has operated with an IT infrastructure model that requires a complete redevelopment to
meet current and future business challenges. The company considers the old IT facility as a
bottleneck and cannot continue to run the different services on that platform because it would
lead to decreased performance, failure of some services or an eventual breakdown of all
activities. Therefore the company seeks professional services to design the new network and
build a solution that meets a list of desired requirements. The sections of this document discuss
and propose best approach towards delivering a quality solution for transitioning to the new
platform. Concluding the design process are an IP addressing plan and models for the network.

Table of Contents
SUMMARY...................................................................................................................................................2
INTRODUCTION...........................................................................................................................................4
ORGANIZATIONAL DESCRIPTION.................................................................................................................4
REQUIREMENT ANALYSIS............................................................................................................................4
MOBILITY REQUIREMENTS......................................................................................................................5
SECURITY REQUIREMENTS.......................................................................................................................5
BANDWIDTH REQUIREMENT...................................................................................................................5
REMOTE ACCESS REQUIREMENT.............................................................................................................6
LOGICAL NETWORK DESIGN........................................................................................................................6
SECURITY DESIGN....................................................................................................................................7
WIRELESS NETWORK DESIGN..................................................................................................................7
VIRTUAL LANs..........................................................................................................................................7
IP ADDRESS ALLOCATION PLAN...................................................................................................................8
LOGICAL NETWORK DIAGRAM..................................................................................................................11
PHYSICAL NETWORK DIAGRAM.................................................................................................................12
CONCLUSION.............................................................................................................................................13
REFERENCES..............................................................................................................................................14

INTRODUCTION
Enterprise networks are difficult to design, operate and manage throughout their lifecycle due
to their size and complexity. They require a great level of expertise and skills on the different
protocols, technologies and services before any network engineer can attempt to classify a
solution as valid for any network. This proposal is prepared in response to uSoft desire to
transition its network to a new design model that will provide secure access and high-
performance levels for users and applications. The migration is triggered by a lack of capacity in
the current infrastructure to support the required applications and services. This redesigned
network will be the key to continual scaling of the network infrastructure and services. The
network design for uSoft will consist mainly of efficient IP addressing design, virtual LAN design,
and service integration focused on redundancy, security and service uptime.
ORGANIZATIONAL DESCRIPTION
The company uSoft is a biomedical software development company with a desire to serve at
100% the market it targets. The company has grown from its inception of a single office space
to a HQ and two branches across the gold coast area. With an experienced team of leadership
that is determined to establish her presence and expand into other markets in the future. The
company is on the verge of achieving the success only a few other companies in her service
area dare to dream about or challenge themselves to attempt.
The biomedical filed is full of advancements and multiple discoveries that can be challenging to
come by without the use of technology. Computing is at the center of these discoveries because
it simplifies or in some instances create new methods for understanding research and
development. uSoft faces a huge challenge of reviewing the current infrastructure that has
served her customers over the years and replaces it with a newer and better network model.
The company believes that a new model that targets her core services must be implemented
and require less review as more services are added to the infrastructure platform.
REQUIREMENT ANALYSIS
IT design requirement analysis is a key planning activity seeking to ensure that the designer and
the client understand what an acceptable solution should deliver. Before arriving at the list of

requirements for the new network a painstaking questionnaire and review process has
validated the goals I now seek to establish through the use of technologies. There are two
aspects of the requirements, business goals and technical goals. This section discusses these
goals how they will be attained.
MOBILITY REQUIREMENTS
The mobility of network users focuses on creating and changing the traditional workspace thus
permitting them to connect mobile devices and move with ease without losing connectivity.
Mobility can only be feasible with wireless technologies. Wireless signals are transmitted as RF
waves and can fill a space and extend based on signal strength levels. At the HQ a wireless
design will be integrated with the LAN network in order to achieve this goal. When
implementing the network, user authentication will be applied as a security measure to deter
unauthorized access to the network that could lead to a security breach.
SECURITY REQUIREMENTS
Security for the internal segments of the network begins with an assessment of the tolerable
levels of risk associated with the absence of appropriate security measures. When the risk of a
breach is quantifiable cost of an attack know businesses can increase spending to ensure a safe
environment is created. Networks can be secure using host-based solutions or network-wide
solutions. The combination of these two creates a formidable defense against any type of
security threats. Infrastructure design focuses on network solutions such as Firewalls, web
security and gateway security devices that can protect the entire network. In this design, a
firewall solution will be deployed and integrated with other networking hardware to secure
users and protect data.
In order to complement security of the internal segments of the network, use of a demilitarized
network zone (DMZ) as a buffer for services will be implemented in the new design. Some
serves will be placed in the DMZ zone where external users can connect while other services
that are solely available for trusted users will connect to the internal network.
BANDWIDTH REQUIREMENT
Network bandwidth measures the speed of connection between nodes on the network. Slower
connection links are termed as having slow speeds and less preferable for some applications.

Some applications exhibit certain adverse behaviour when the bandwidth drops below
acceptable levels. Voice and video applications top the list of services that require bandwidth
reservation and quality of service provisioning. Implementation of adequate bandwidth will be
reflected in the choice of networking hardware and link type to connect the different devices.
Acceptable speed range are either fast Ethernet (100Mbps) or Gigabit Ethernet speeds
(1000Mbps).
REMOTE ACCESS REQUIREMENT
Remote access users have become the norm in many workplaces where a designated group of
staff can connect remotely to the enterprise network over a WAN connection. This requires the
configuration of remote access policies and services profiles using a virtual private network. A
VPN is an ideal solution because of the security it can provide over the untrusted public
network. The main concern for users connecting remotely is authentication and security of
network traffic. Remote access VPN also permits users to connect via a wide range of personal
computing devices. The previously mentioned Firewall appliance will terminate all remote
access before permitting access to the LAN network.
LOGICAL NETWORK DESIGN
A logical network is a reference model that can be used to implement a proposed set of design
objectives. It contains the information that can be used to implement an architectural model
for services on the network. A logical model does not depict the actual location of the network
devices but aid network engineers in the choice and final network build process. A viable model
that can be tailored for the current network is a campus network. A campus network is a
hierarchical model with multiple layers of infrastructure devices each providing unique services
for users. The basic campus model is made up of the core, distribution and access layers. A
preferable model of the network collapses the core and distribution layers into a single layer
leading to a two-layer hierarchical model. In this two-layer model, the core connects to the
internet edge while the access layer connects to end host devices. The advantage of using this
model is the scalability it provides by enabling additional devices to be added to the network
without disrupting the any functional services (Shin, 2017).

SECURITY DESIGN
Designing for security requires ardent planning and proper placement of devices on the
network for effectiveness. Integrating security into the current topology which is only centered
on the HQ network simplifies the entire design process. To achieve this, a redundant pair of
firewalls will be placed between the edge routers and the distribution layer switches. This
creates multiple zones between the different devices (internal, external and DMZ). Security
filtering, policies and access control mechanism can easily be deployed on the network. The
VPN for remote access users will be configured on the firewall appliance.
WIRELESS NETWORK DESIGN
To create a unified converged infrastructure that supports all services and integrate mobility,
wireless access points will be placed at multiple points in the building plan layout. Each access
point has a coverage area although it is ideal to allow overlapping of wireless signals across an
area. A total of six access points would be adequate to cover the workspace for the HQ office.
The AP’s will be plugged into the access layer switches. To simplify the deployment switches
that support power over Ethernet (PoE) will be a best choice for the design. Network users
connecting to the wireless network will be authentication by the Aps before their traffic is
forwarded to the network.
VIRTUAL LANs
Designing a network without VLAN segmentation introduces enormous challenges that could
eventually cause the network to be unusable. The benefit of a VLAN is that we can control the
size of the broadcast domain and easily administer control to any user segment. Without
VLANs, any increase in the size of the network might require overhauling of the design, new
equipment or translate to a negative output for users. In the HQ LAN, segmenting the network
into the various department resulting in six VLANs and afterwards replicating same for network
resources.

IP ADDRESS ALLOCATION PLAN
When an IP address block is assigned to a network, the administrator subnets the large address
space into smaller subnets based on the LAN requirements for each network. A subnet scheme
is designed to identify the addresses used on the network, assign host addresses and define
usage of network logical addressing. IPv4 addresses are a 32bit decimal value that are
separated into 4 octets. The range of decimal value is from 1 to 255 within each octet. An
accompanying decimal value called the subnet mask differentiates between network and host
portion of the address. A network portion identifies a device location on the network while host
addresses are assigned to the network interface card (NIC) on a host.
The addressing scheme for the uSoft HQ LAN network will use the variable length subnet mask
scheme and the allocated address. The assigned prefix is 172.16.1XY.0/22 where XY is the first
two digits of my student ID and is decimal value 23, the assigned address block becomes
172.16.123.0/22. The size of the networks for each department will be computed based on the
information provided. In each department there each user has a PC and a phone in addition to
servers for internal access.
1. Software development: 207 host addresses
2. Solutions design: 186 host addresses
3. Customer support: 125 host addresses
4. Sales: 95 host addresses
5. Finance: 65 host addresses
6. Human resource: 45 host devices
To apply the VLSM scheme the networks will be subnetted from the largest to the smallest.
Software dev. LAN has 207 host devices, the number of host bits for the assigned address block
172.16.123.0/22 is 10bits.
207 devices require 8 host bits, subtracting 8 from 10 leaves 2 bits for creating new networks.
Number of host is 2^8-2 = 254, number of networks = 2^2 = 4.
The new subnet mask is 255.255.255.0 or /24

The new networks are: 172.16.123.0/24, 172.16.124.0./24, 172.16.125.0/24 and
172.16.126.0/24.
The first subnet 172.16.123.0/24 can be assigned to Software development.
Analyzing the host requirements for the next largest subnet wit 186 host addresses, indicates
that 8 host bits are required for this LAN segment.
Assign 172.16.124.0/24 to Solutions designs
Next, we analyze the host requirement for customer support with 125 host addresses. This
requires 7 host bits. Using the next available subnet 172.16.125.0/25 with 8 host bits,
subtracting 7 bits gives 1 bit for the network.
Number of host = 2^7-2 = 126
Number of new networks = 2^1 = 2
The new subnet mask is 255.255.255.128.
The new networks are: 172.16.125.0/25 and 172.16.125.128/25.
Assign 172.16.125.0/25 to the customer support LAN segment.
Additionally, the Sales department with 95 hosts requires 7 bits. We can, therefore, assign the
next network 172.168.125.128/25 to Sales LAN.
For Finance department with 65 host addresses, this requires 7 host bits. The last network
address 172.16.126.0/24 has 8 host bits. The difference between this values gives us 1 bit for
the new networks.
Number of host = 2^7-2 = 126
Number of networks = 2^1 = 2
The new networks are 172.16.126.0/25 and 172.16.126.128/25.
Assign 172.16.126.0/25 to the Finance department LAN.

Finally, the human resources department requires 6 host bits for 45 host addresses.
Consequently, we have 1 bit for network portion.
Number of networks = 2^1 = 2
Number of host = 2^6-2 = 62
The new networks are 172.16.126.128/26 and 172.16.126.192/26.
Assign 172.16.126.128/26.
The complete IP addressing plan is present in the table below.
LAN
NETWORK
NETWORK
ADDRESS
SUBNET MASK GATEWAY HOST ADDRESS
RANGE
BROADCAS
T ADDRESS
SOFTWARE
DEV.
172.16.123.0 255.255.255.0
OR /24
172.16.133.1 172.16.123.1 -
172.16.123.254
172.16.123.
255
SOLUTIONS
DESIGN
172.16.124.0 255.255.255.0
OR /24
172.16.124.1 172.16.124.1 –
172.16.124.254
172.16.124.
255
CUSTOMER
SUPPORT
172.16.125.0 255.255.255.12
8 OR /25
172.16.125.1 172.16.125.1 –
172.16.125.126
172.16.125.
127
SALES 172.16.125.128 255.255.255.12
5 OR /25
172.16.125.129 172.16.125.129
–
172.16.125.254
172.16.125.
255
FINANCE 172.16.126.0 255.255.255.12
8 OR /25
172.16.126.1 172.16.126.1 –
172.16.126.126
172.16.126.
127
HUMAN
RESOURC
E
172.16.126.
128
255.255.255.
192 OR /26
172.16.126.
129
172.16.126.1
29 –
172.16.126.1
90
172.16.1
26.191
Table 1:IP address allocation plan
(Oppenheimer, 2004)

LOGICAL NETWORK DIAGRAM
The diagram of the logical network is presented below. It shows the details of connectivity links
and devices for the LAN at the HQ.
Figure 1: Logical network design

PHYSICAL NETWORK DIAGRAM.
A physical network diagram concluding the design for uSoft HQ LAN is presented below. The
diagram depicts how the physical LAN network for the campus hierarchical design.
Figure 2: Physical network topology