Essays on Data Link

Source: InfoSec Institute Web article, January 2016

Summary: This article was about Information security governance and Risk Management in CISSP domain. In the article some basic guiding principles for the security are highlighted, the security's fundamental principles revolve around the CIA i.e. confidentiality, integrity and availability. Confidentiality confirms that the data is confidential through personal identifying information, integrity ensures the accuracy of the data and it is not modified by anyone else and finally availability ensures that whenever the data is needed, it is available i.e. no DOS attacks or any other attacks stops the access of the data. The risk management talks about the analysis ...

Internet of Things

Abstract page Internet of things (IOT) refers to a system of interconnected digital and mechanical machines, computing devices, objects and things which have their own unique identifiers and ability to transfer data and communicate over a network without the need of any human interaction. The term IOT was coined in 1999, but became famous after the onset of RFIDs. It is estimated that by 2020, around 30 billion devices around the world will be wirelessly connected to the internet of things. The research on IOT has been going in various fields like healthcare, home systems, retail, transportation, insurance etc. ...

Exploring the Transport Layer

The Transmission Control Protocol (TCP) over IP protocol (TCP/IP) protocol suite has four layers: link, network, transport and application layers. TCP and User Datagram Protocols (UDP) operate at the transport layer and TCP is connection oriented and ensures data delivery while UDP is connectionless and has no mechanism to check data delivery. In the “three way handshake” in TCP, the sender/client sends a connection request to the server using a SYN (synchronization) message (a bit flag in the TCP header sent with an initial sequence number and the maximum transmission size (MTU)). On receipt of the SYN message, the ...

Financial discrepancies are part of the issues affecting companies today. It is worth noting that forensic investigation in a computerized work environment solves fraudulent activities. This process demands high-level expertise in forensic investigation. A forensic investigator uses various steps in investigating an employee computer. The forensic expert has to follow various steps during the investigation process. These include planning stage, gathering information stage, review process, and reporting. Investigation on employee computer is streamlined towards finding out the fraudulent activities, where and when it took place, identify those involved and quantify the monetary value of the fraud. Getting authorization to ...

Final Assignment

Both Bridges and Switches work on the data link layer of the OSI Model. However, switches are more advanced. Discuss how a switch has an advantage over a bridge in a network then elaborate more on the technology implemented in switches to control broadcast domains A bridge is a two interfaces device that creates two collision domains. This is because it forwards the traffic received from one interface only to the interface where layer two devices is connected (Olenewa, 2014). Bridges serves the main function of reading the destination of MAC address to forward the traffic only to the interface where it ...

1. Discuss the role of networks within different organizations and the resource implications of networks.

Of late, networks have become a principal mode of data transmission helping in collaboration, dissemination of knowledge, creative reproduction and gathering resources to undertake research. The networking system is integral to organizational function. Within different organizations, networks play the following roles:

- The network of an organization helps the employees increase their productivity by allowing them exchange ideas quickly. - It keeps the employees connected all the time from anywhere by allowing them remote access. - As there are several computers connected to a ...

The data link layer (layer 2) of the OSI model, specified by IEEE standard 802.2 is divided into two sub-layers; the Media Access Control (MAC) and the Logical Link Control (LLC) sub-layers. LLC sub-layer is bounded above by the network layer (OSI layer 3) and below by the MAC sub-layer. It thus provides services to both of these layers. LLC frames data into Protocol Data Units (PDUs) by adding a header that contains the control information used for error control and flow control. The header also contain the Source Service Access Point (SSAP) and Destination Service Access Point (DSAP) ...

Frame relay

Frame relay is method of network transmission whereby the frame is designed to operate in virtually error-less circuits. This protocol is stripped down to enhance transmission speed. The method operates in a manner that network layer of the OSI model is created and the routing process and multiplexing roles is performed by itself and hands over everything else to the levels higher in the network transmission hierarchy.

Frame relay omits the former roles such as sequential ordering, window rotation, acknowledgement of frames, and automated retransmission in case of failure so as to focus on the fundamental roles which is fast ...

[Author Name(s), First M. Last, Omit Titles and Degrees] [Institutional Affiliation(s)] [Include any grant/funding information and a complete correspondence address.] Network security is a means to assure that unauthorized access to assets in the network is prevented. This is vital if we have to protect the CIA triad of Information security, which is to protect the Confidentiality, Integrity and Availability of the data. Unauthorized access could violate one of more of the CIA triad’s principals. These unauthorized accesses also cause loss of accountability and nonrepudiation of actions. This paper examines the concepts of Network Security ...

Acronyms and Glossary

OSI – Open System Interconnection UDP – User Datagram Protocol is one of the important transport layer protocol used for internet that allows computer applications to send messages.

TCP – Transmission Control Protocol is one of another internet communication protocol

DSL – Digital Subscriber Line is a technology that provides an internet access and transmits digital data over the local telephone line.

UTP – unshielded twisted pair widely used for local area networks

Hub – A hub is a device to connect multiple Ethernet devices RJ45 – A connector standard used for Ethernet connections and telephone cables Introduction Lindley Hall is a steel and limestone building and has 5 stories. The client wants to connect approximately 1000 computers in the building. Out of these 1000 computers, ...

The connectivity issues between the end user and the DB Unit 2 can be understood with the help

Of OSI model reference. First a small description about OSI model.

Layers of OSI model:

1. Application Layer: Acts as an interface between the user and the software itself. 2. Presentation Layer: It is responsible for data representation, encryption and decryption. 3. Session Layer: Starts, maintains and terminates all new or ongoing sessions. 4. Transport Layer: This layer ensures reliability and flow control, either by TCP or UDP. 5. Network Layer: Provides the best path or selects the route between the source and the

Destination.

6. Data Link Layer: It is responsible for transferring data between network entities and also

Corrects errors that may occur in the physical layer.

7. ...

Routing: the network layer is the one responsible for routing packets in the network. The network layer is responsible for host-to-host communication. To facilitate communication a global addressing scheme is used to identify the host computers in the network. The address is used for routing packets to the destination computer. During packet routing in the network a number of problems may occur that may prevent the packet from reaching its destination. Some of these issues may include the incompatible in addressing between the sending and the receiving computer. In some case the packet size compatibility issue may also arise, differing protocols ...

The automatic dependent surveillance-broadcast (ADS-B) is a technology that is used in tracking aircraft. This system is much different from the radar system that works by bouncing radio waves back from the terrestrial fixed antennae from airborne targets and interpreting the signal. The technology uses the typical Global Navigation Satellite System (GNSS) technology and a simple broadcast communication link as its basic components. Additionally, unlike the conventional radar system ADS-B’s accuracy is not interfered with range, target altitude or atmospheric conditions. The update intervals is also not dependent on reliability of mechanical antennae’s or rotational speeds (Weijun, Tong, & Wentao, ...

The 20th century has seen tremendous changes in telecommunications sector where there has been great improvement in communication. The major examples of telecommunications sectors which have greatly developed over the century are computer communication, telephony and telegraphy. There has also been a major revolution in the communication media being used in interconnecting the communicating gadgets. However, some media have remained dominant and still hold a significant role in contemporary telecommunications sector (William, 2007). Narrowing down to computer networks, they can be defined as a collection of interconnected nodes (end devices). Much precisely, a network is a medium that allows passage of data across ...

The ping function is an inbuilt command used by a computer to access a certain resource on the internet by command. The most common ping function is done from the command window in Microsoft windows operating systems. This function allows a person to send a command to a certain internet connection (IP address) and receive a reply from the pinged resource or device (ftp.arl.army.mil/~mike/ping.htm, paragraph 2).

In the ping function, a computer sends a command to the device it wants to access or resource and waits for a reply. The reply time varies according to the strength of the connection and the connectivity if it is done ...

TCP/IP Framework

TCP/IP stack is a set of hierarchically ordered network protocols. The name of the stack represents a combination of two major protocols – TCP (Transmission Control Protocol) and IP (Internet Protocol). Apart from them, there are dozens of different protocols in the stack. Currently, TCP/IP protocols are the main ones allowing the Internet existence, as well as functioning of the majority of corporate and local area networks. The history of TCP/IP started in 1967, when the Defense Advanced Research Projects Agency (DARPA) initiated development of computer network, which was to link a number of universities and research centers, performing orders for the ...

The Network, Data Link, and Physical Layers

Introduction

The OSI (Open Systems Interconnection) model has served as a reference for the most basic elements of computer networking since its inception in 1984. Based on a proposal created by the International Standards Organization (ISO), the OSI model was developed “to provide a set of design standards for equipment manufacturers so they could communicate with each other” (Miller, 2001). It consists of seven layers, which, from top to bottom, are the following: Application, Presentation, Session, Transport, Network, Data Link, and Physical.

I have learned, through the research I conducted, that the three upper layers perform the application-specific functions such as connection ...

The Top-Down Approach

Network Architecture and Design: The Top-Down Approach

Network architecture and design are many times two separate stages in a network implementation project. McCabe (2007) identifies network architecture as a higher level concept of a network. He says that it focuses on more general relationships between the major components of a network. For example, "addressing and routing, network management, performance, and security." (p. 211). The design stage of the project normally starts after the higher level architectural plan has been approved. This is where the real detailed work starts and the nuts and bolts start to come together. In designing your network, ...

1. What is a local area network?

Local area network (LAN) is a type of computer network that connects devices and computers within a limited geographical area, such as school, home, office building or computer laboratory (“Local area network,” n.d.). Its main distinguishing characteristics from wide area networks are smaller and limited geographic area, higher rates of data transfer and absence of need for leased telecommunication lines. It is convenient to use LANs in the areas with limited space, which can be as small as one apartment, or as large as a university campus. They are also often used for business purposes, as they have a number of benefits that ...

Technology

Introduction

A network switch is a small hardware device that is used to connect two or multiple computers within a local area network (LAN). This enables the paring of the computers hence sharing of information is facilitated. The networking switches normally operate at a layer two that is data link layer of the Open Systems Interconnection model (OSI). Network hubs are very similar to network switches but after close scrutiny, a network switch can inspect data packages received, can determine the final destination while sourcing the original source of the data. They deliver the message to the devices connected to the network hence ...

The open system interconnection model (OSI) is based on the open system interconnection. The communication system is sub divided into layers with each layer providing services to the other layers (Behrouz, 2006, p. 17). This model is composed of seven layers arranged logically in order from the physical layer to the application layer. The physical layer performs majorly electrical and mechanical aspects of the network. These includes the establishment and termination of connection to a physical medium and conveying bit streams in form of electrical impulse, light or radio signal. The physical layer protocols are the ATM, RS232 and ...