Network Security & Protocols: Multiplexing, Routers, ARP & TCP Windows

This assignment delves into various aspects of network security, starting with the multiplexing mechanisms in the LCC sublayer and their role in error control. It explains how routers connect different physical networks using multiple network interface cards (NICs) to reduce redundancy. The assignment also discusses the dynamic mapping of MAC addresses to IP addresses during internet connections using the Address Resolution Protocol (ARP). Furthermore, it covers the modification of Ethernet headers when routing data packets to new destinations. The solution also addresses port number allocation, the TCP handshake process for establishing connections, and the use of TCP window size for flow control. Finally, it touches on the differences between type 1 and type 2 virtualization products and provides an overview of the evolution of cellular networks from 1G to 4G, including the technologies they employ and the roles of mobile switching centers and base stations in managing cellular communication. Desklib provides access to this and similar solved assignments.

NETWORK AND SECURITY
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Topic 4.
Question 5.
The multiplexing mechanisms in the LCC sublayer within a multipoint network provides the error
control mechanism through provision of repetitive requests automatically with the flow control and
management.
Question 7.
To be able to connect to different physical networks, routers are made with several network
interface data cards that help in the reduction of the redundancy in the network and data. In the
event that one NIC is corrupted, the other functions in its place to reduce data redundancy.
Question 19.
During the internet connection, the MAC address is successfully mapped with the internet protocol,
and an entry, that is new, is added to the address resolution protocol. The addition of entries is
dynamic to allow static entries to be added. The MAC address, using a predetermined time, can be
removed from the address resolution protocol using a set time depending on the disconnection
status of the network.
Question 20.
The header of the Ethernet is modified following the addition of a new address on the router to send
the data packets to the new destination.
Topic 6.
Question 5.
Located from 0 to 65535, storing port number destinations are counted and therefore one is added
to the maximum value 65535 to determine the number of bits to be used as storing port destination
number 65536.
Question 8.
A new port is allocated when a new tab is opened on the web browser and a network connection is
attempted each time. Because the data packets are labelled specifically for each port, the data is not
interrupted nor modified.
Question 14.
The handshake process is carried in 3 steps.
The steps are:
The client attempts a connection to the server via the network.
The server acknowledges the connection by giving a feedback.
The client acknowledges the response from the server.

Question 15.
The TCP window size field implements the flow control. The client specifies the maximum byte that
can be received without acknowledgment, the receiver meanwhile slows or stops data sending
through delaying the acknowledgement.
Topic 8.
Question 5.
Type 1 virtualization products are found on the firmware while type 2 products are located on the
operating system.
Question 8.
1G cellular networks supported only voice and had a frequency of 30Hz.
2G networks allowed switching between voice and data with the support of voice, data, short
messaging and multimedia messaging.
3G supports high data speeds basing on the CDMA technology.
4G allows very high data transfer speeds and mostly utilizes the LTE technology based on IP.
Question 9.
To distribute the cellular network over a wide geographical area, cells are used.
The mobile switching centre controls and manages the network interfaces and telephone services
allocation to the public.
Base station is the network’s communication point that is fixed.
Question 10.
The mobile switching centre manages and controls the user devices allowing them to shift from one
cell to another. The base station then receives the new traffic after changing from one cell to the
other.
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