Networking Hardware and Operation

Computer Networking is a type of telecommunication network that incorporates a linked network of various computing devices and is also a medium to share resources. This report wholly discusses about how the connectivity is made among computing devices and systems. It also includes a brief overview of layers of OSI model and TCP/IP referencing model that makes this connectivity possible.

Lecture-1

This lecture describes how the data is transmitted over any network, starting from number system which enables any computer to understand the inputs and translate the values to give the desired output. There are four number system that are used in networking.

1. Decimal number system with base 10, it represents quantities and addresses IPv4 protocol. (Mirkovic, Dietrich, Dittrich, & Reiher, 2004, p.7).
2. Binary number system represents how the data is stored into the system and it can be used to examine bits in data.
3. Hexadecimal number system addresses IPv6 protocols and represents relatively larger quantities. Basically it is a shorthand way to write large binary numbers.
4. Octal number system is used for modifying Linux permissions.

Wireshark is a Protocol Analyser and thusly can catch the parallel information that comprised arrange movement and after that dissect and show that information in approaches to enable us to comprehend it. Wireshark is use all through the systems administration industry as isn’t just vital to us, yet in addition to arrange engineers around the world.

Virtualization supports server farms around the world. We are just worried about its utilization as a work area client; anyway its venture into industry is significant.

Lecture-2

In this, operation of basic networking hardware like NIC, Hubs, Switches and routers is discussed. In Circuit Switched systems a committed channel is set up before information being sent. (Shin, 2010) The best case of a circuit exchanged system is the Plain Old Telephone System (POTS) as utilized in numerous organizations and homes. Once the circuit is set up, you and the individual on the opposite end of the phone successfully have a wire interfacing the two phones for the span of the phone call. This course anyway is basically worried about Packet Switched systems. Example of packet switched network is ARPANET. It stands for Advanced Research Projects Agency Network. It incorporates both packet switching and TCP/IP protocols. Earlier Interface Message Processors (IMPs) were used to connect to network and nowadays routers fulfil the need.  

Packet Switching is done in offices using Wifi, cables in homes, larger networks like business or university networks using optical fibre. This devices are interconnected by NIC cards, routers, network hubs etc. The data transmission over the network is based on two network models i.e. OSI and TCP/IP model. These models can handle small packets of data. For large amount of data transmission it has to be fragmented (at the beginning) and reassembly at the destination. The transmission of data is described by these two network models.

OSI and TCP/IP Referencing Model

Lecture 3

OSI and TCP/IP referencing model is a virtual model that shows how the data is transmitted over network. These two models have different number of layers. OSI has seven layers whereas TCP/IP has 4 layers. (Hidalgo, Siu, Nemunaitis, Rizzo, Hammond, Takimoto, Ferrante, 2001, p.7).

Application layer is common in both models. This layer is the user interface and enables user to get access to interact with thousands of services and devices over the internet and on local network. It has categories of interaction:

1. Client/server architecture- In this client request services from the server like a web client request web pages from web servers.
2. Peer to peer architectures- In this, each machine in the system can go about as both a server and a customer (at the same time if required). All machines (peers) can share assets (document and printers) and can likewise get to any mutual asset.
3. Host based architectures- Each system has mainframe connected to terminals and this mainframe performed all the processing.
4. Cloud based architecture- It can supply a scope of administrations to associations including the processing stage, working frameworks and programming.

Lecture 4-

Data link layer is a network interface layer. The Data Layer only communicates with devices on its local network. There are two sub layers of data link layer i.e. logical link layer (LLC) and Media access control (MAC). LLC is the upper interface layer which allows IPv4, IPv6, IPX and other transaction concurrently whereas MAC sends traffic to the network media and receives traffic from the network media. Network Interface card have a 48 bit MAC address and this address is used for communication. NIC cards are smart devices as it inspects every packet on the local network. Media Access Control is worried about mediating access to the system. In controlled access just a single station can transmit at once. Gadgets needing to transmit must sit tight. Token Ring and FDDI are two cases that utilization this kind of media get to control. This lecture involves other terms such as CSMA/CD, CSMA/CA and ARP.

CSMA/CD- Carrier Sense Multiple Access with Collision Detection. This is the Media Access Protocol utilized by Ethernet. Ethernet is the most broadly utilized Data Link strategy for associating PCs and different gadgets to a network. This media get to technique enables various PCs to all utilization a typical system media. One issue is that crashes can happen when two machines attempt to send an Ethernet bundle at the same time.

CSMA/CA- Carrier Sense Multiple Access with Collision Avoidance. From multiple points of view this Data Link convention works comparably to CSMA/CD anyway the stations attempt to keep away from crashes by saving the system media. Before transmitting an information outline a station can send a Request to send casing to the Wireless Access Point. The Access Point sends a Clear to Send (CTS) edge to the remote network. The CTS holds the system for the asking for station for a predefined time of time. The asking for station sends the edge without dread of an impact.

Data Link Layer: Network Interface Layer

ARP- System Operating Systems (like Windows and Linux) keep up a table in RAM (called the ARP store) that contains the IP Address and MAC address of machines that have been reached as of late.

Lecture 5

Address resolution protocol (ARP) decides the MAC address of a machine on the neighbourhood connects with a particular IP address. It communicates message getting some information about the IP address proprietor and if the framework reacts, MAC address is known and is gone into ARP cache. (Zimmermann, 1980, p.7).

The Internet (Network) layer conveys arrange movement starting with one host then onto the next. The two hosts are frequently isolated by long separations. It has a part of Sending the bundle to the neighborhood switch and let it handle the remote conveyance of system movement. Every gadget on an IP network requires an IP address. There are two sorts of IP address: IPv4 and IPv6 respectively.

Network Address Translation (NAT) – The PCs (has) on most home systems utilized private IP addresses (assigned by the DHCP server in the switch). Home system switches utilize NAT to give Internet access to those hosts. (Fall, & Stevens, 2011, p.7). 

DNS (Domain Name System) – Name goals of Internet names is dealt with by DNS. Name goals is the way toward looking into the IP address of an Internet name, or for invert queries, deciding the host name of a specific IP address.

Lecture 6

The transport layer terms is discussed in this lecture. It keeps up the exchange of information bundles between the layers. Application regularly share expansive stream of information and this layers breaks vast pieces of information into little measured fragments so the switches can deal with them thus numerous applications can gain admittance to the system (this is called multiplexing). At the goal, the divided information must be reassembled by the vehicle layer once again into the organization sent by the sending application. This is called reassembly. Reassembly may likewise include reordering in situations where bundles were conveyed out of request. Transport layer has two conventions:

Client Datagram Protocol (UDP) gives essential transport administrations to arrange applications. The UDP header determines the source and goal port numbers, the length of the UDP header (in bytes) and a checksum. In UDP correspondences no checking is done to guarantee parcels arrive securely. TCP is an association arranged convention. It ensures dependable and all together conveyance of information from sender to recipient.

Lecture 7

The first layer of both the models is physical layer. The data is transmitted over the network in the form of analog and digital signals. Frameworks can likewise be classified by the manner in which information streams between gadgets. Simplex framework can just send information one way. Half-duplex framework permit information stream in both directions.But just one way at any one time. (Forouzan & Fegan, 2002, p.7). Full duplex permits information stream in the two bearings simultaneously. Further multiplexing is discussed as it is an important part of physical layer. Multiplexing is utilized to isolate up an interchanges channel so the channel can transmit numerous discussions at the one time. There are many transmission media for transfer of data in physical layer that are unshielded twisted pair, shielded twisted pair, coaxial cable, optical fibre etc.

References

 Mirkovic, J., Dietrich, S., Dittrich, D., & Reiher, P. (2004). Internet Denial of Service: Attack and Defense Mechanisms (Radia Perlman Computer Networking and Security).

Shin, D. H. (2010). The effects of trust, security and privacy in social networking: A security-based approach to understand the pattern of adoption. Interacting with computers, 22(5), 428-438.

Hidalgo, M., Siu, L. L., Nemunaitis, J., Rizzo, J., Hammond, L. A., Takimoto, C., … & Ferrante, K. (2001). Phase I and pharmacologic study of OSI-774, an epidermal growth factor receptor tyrosine kinase inhibitor, in patients with advanced solid malignancies. Journal of clinical oncology, 19(13), 3267-3279.

Zimmermann, H. (1980). OSI reference model–The ISO model of architecture for open systems interconnection. IEEE Transactions on communications, 28(4), 425-432.

Fall, K. R., & Stevens, W. R. (2011). TCP/IP illustrated, volume 1: The protocols. addison-Wesley.

Forouzan, B. A., & Fegan, S. C. (2002). TCP/IP protocol suite. McGraw-Hill Higher Education.