Networking Fundamentals: Data Communications and IP Calculation

This document presents a comprehensive solution to a data communications and IP calculation assignment, addressing key networking concepts. It begins with an overview of the OSI model, detailing the functions of each layer from the physical to the application layer. The assignment then delves into IP subnetting, providing a hands-on project that demonstrates IP address calculation using an online subnet calculator and includes a Wireshark project to analyze IPv6 packets. Further, it explains the roles of IP, MAC, and ARP protocols in data communication, emphasizing their importance in network device identification and data routing. A case study is presented, outlining the requirements and design of a network, including detailed IP addressing for various departments and routers. Finally, the document touches upon the upgrade from IPv4 to IPv6, highlighting the dual-stack approach for compatibility.

Running head: DATA COMMUNICATIONS AND IP CALCULATION
Data Communications and IP Calculation
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Question 1: Different layers of OSI model and their roles
Functions of OSI layers
The seven layers of the OSI reference model each perform specific set of functions.
Physical layer, the first layer of OSI is responsible for conveying a bit stream of light signal
and electric impulse. Data can be send and received by means of hardware which can include
network cards, motherboard sections and cables. Protocols associated with these components
of the physical layer can be RS232, fast Ethernet and ATM. OSI model’s second layer is the
data link layer which involves encoding and decoding of data packets takes place (Zhao et al.,
2018). It is also used in furnishing knowledge of transmission protocol and handling errors
surrounding physical layer. The network layer or third layer of OSI model is responsible for
providing routing and switching mechanisms through virtual circuits that are used to transfer
data packets from node to node. The transport layer or fourth layer of this model ensures
complete transfer of data between hosts and end system. The session layer or fifth layer of
OSI terminates, establishes and manages connections among the applications. The
presentation layer or sixth layer, helps in convert data into forms, which is understandable for
the application layer. The application layer or seventh layer supports the application
processes and the end-users processes (Alotaibi et al., 2017). Service quality, communication
pattern, data syntax constraints are identified and privacy and authentication of user are
considered.
The application, session and presentation layer are the software layer whereas
network, physical and data link layers are the hardware layers. Transport layer, heart of the
OSI model separates the software and hardware layers.
The internet layer perform the function of packet switching networking that is based
on the connectionless network layer. This layer is responsible for holding the whole

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architecture of the model. This help in free moving of the packets over the internet. The order
of receiving and sending the packets are different. This layer uses Internet Protocol. Whereas
the network layer allow the interconnection of different networks. The networking layer of
the OSI model is compared to the TCP/IP model. The network layer routes the data from
node to node and the internet layer transfer the data packets and provides routing facility over
the internet (Goralski, 2017). Both these layers are engaged in transferring data packets but
internet layer transfer it over internet so it called as internet layer in the TCP/IP model.

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Question 2: IP Subneet Calculation
Hands-On Project 2.3
1. & 2. Enter the addresss www.gestioip.net/cgi-bin/subnet_calculator.cgi and in the web
page that opens please check that ipv4 radio button is chosen.
3. In the IP address field give the IP 192.168.0.0 as input

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4. The appropriate subnet mask for the class C IP address 192.168.0.0 that is 24
(255.255.255.0 – 254) is chosen from the BM dropdown and then calculate is button is
pressed to find the results.
5. The results of the of the subnet calculation is provided, since 192.168.0.0 is a class C IP
address, the bitmask is 24 and in the last line the IPv6 address mapped to this IPv4 address is
given.

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6. Then the browser is closed by clicking the cross button.

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Hands-On Project 3.2
Wireshark is started
Ethernet is chosen as it carries the configured IPv6 address 2001::109
On clicking start recording is started.

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By entering ‘cmd’ in run, the command prompt window is opened.
The IPv6 address of another computer in the LAN network is pinged.

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After the successful result, the command prompt is closed with the ‘exit’ command and the
wireshark recording is also stopped.
Next the the packets recorded in wireshark are filtered using the ipv6 filter.

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One of the ipv6 packets is selected from the list.
The IPv6 field of the packet is then expanded.

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Thereafter, in the IPv6 field, the traffic section is expanded.
Contents of the IPv6 field of the packet are:
Payload length: 40
Next header: ICMPv6 (58)
Hop limit: 128
Source: 2001::108

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Destination: 2001::109
The IPv6 field is then collapsed
The wireshark file is then saved as ch03_IPv6Fields and wireshark is closed.
Question 3: Role of IP, MAC and ARP protocols
There are two type of address for every network device. The IP address is the logical
address and the MAC address is the physical address. In a local area network a hardware