Advanced Research Project Agency ( Arpa ) Of Defense ( Dod ) And International Standard Organization

But how does it work? The internet, based on the concept of “packet switching”, involves the travelling of small packets of data over one or more networks (Frenzel, 2013). This can be compared to “electronic postcards”, meaning that “a computer generates a piece of data and flings it into the net, just like the postal system, except 100 million times faster” (Cerf, 2013). This concept allows one computer to speak to many different computers around the network by sending out these “electronic postcards”. However, before these networks can work seamlessly together, they must use a common protocol, or set of rules for transmitting and receiving these packets of data. There are several protocols currently in use, including the OSI Model, the TCP/IP Model, UDP, HTTP, and FDP (Mitchell, 2014), but the most commonly used is Transmission Control Protocol/Internet Protocol (TCP/IP) (Gilmer, 2011). Even as early as 1977, TCP/IP was being used by other networks to link to ARPANET (Kozierok,

3: Network Layer: The use of network layer is switching and routing technologies. It demonstrates logical path and virtual circuits for transferring data from one node to

Patton-Fuller Community Hospital uses layers 1, 3, 4, 5, 6, and 7 of the OSI model. The OSI model is broken into seven layers that play a major important role in how the model functions on a functioning level. Patton-Fuller Hospital uses certain layers of the model, below is the function of each layer:

The fifth layer is the session layer this establishes a connection,this layer makes and sets up the connection using co ordinates and could terminate conversations links. the session layer produces services that make authentication after an interruption and not only that but it can reconnect.and as well as the transporting layer it can also have the TCP and the UDP can provide services for all most all applications.An application layer is an abstraction layer that specifies the shared protocols and interface methods used by hosts in a communications network. The application layer abstraction is used in both of the standard models of computer networking; the Internet Protocol Suite (TCP/IP) and the Open Systems Interconnection model (OSI model).Although both models use the same term for their respective highest level layer, the detailed definitions and purposes are different.In TCP/IP, the application layer contains the communications protocols and interface methods used in process-to-process communications

• “Application - The Application Layer is the layer that most network users are exposed to, and is the level at which human communication happens. HTTP, FTP, and SMTP are examples of the application layer protocols the Patton-Fuller will now be utilizing for communicating electronically” (Network Design, 2012).

1. Application (in terms of cabling infrastructure): The application layer is the OSI layer closest to the end user, which means both the OSI application layer and the user interact directly with the software application. When determining resource availability, the application layer must decide whether sufficient network or the requested communication exists.. (OSI_model#Layer_7:_application_layer)

The OSI (Open System Interconnection) model is a set of specifications that allow computers around the world to openly communicate. It is pivotal to understanding and developing computer to computer communications in a network. Each layer plays a role in the process of sending and receiving data. The application layer is the top layer (layer seven) it promotes communication between programs and lower-layer network services. The services at this layer allow the network to decipher a program's request and the program to decipher data sent from the network. The Application layer protocols, programs handles formatting, procedure, security, synchronization, and any other requirements with the network. The Presentation Layer (layer 6) acts as a translator. For instance these protocols decode the jpg/jpeg files sent within the Web server’s HTTP response. So, in the last step (the Application layer) we enter the Web address and it took us to the Web site. This step allows us to see the images and content of the site. The Session Layer (layer 5) regulates and controls the communication between two nodes on the network. It is an ongoing exchange of data between the two and keeps the connection between them for the duration. It keeps the communication secure, detects whether or not the communication has been cut off and if it has it determines where to restart the

In the seven layers of the OSI, control is passed between layers. The model is theoretical, but tells us how a network takes the data sent from the application all the way down to the physical layer and out, to in the physical layer and back up all the way to the application layer. This Model has nothing to do with the actual functions of the process. Instead it is a concept of the framework, so the complexities of a network can be broken down and understood (Beal, 1999).

It is the software structure, which implements the communication function. The protocol architecture consists of a layered set of protocols, with one or more

As we all know, the growth of computer networks continues to rapidly grow. The digital revolution has changed the way we work and communicate almost beyond recognition. Provided that, foreseeing the changes and potential compatibility problems, in the mid nineteen eighties, the international standard organization (ISO) developed a networking reference model to standardize how network systems communicate with each other. It is a logical model for how network systems are supposed to communicate with each other. It breaks down the different components of the network communication and puts them into layers which reduce complexity. This reference model consists of seven layers: Application Layer, Presentation Layer, Session Layer, Transport Layer, Network Layer, Data Link Layer, and the Physical Layer. Each layer provides a service to the layer above it in the protocol specification and then communicates with the same layer’s software or hardware on other computers. It's important to realize, that these layers are separated into 2 sets: Transportation Set (Laters 1- 4) and Application Set (Layers 5 – 7). More importantly, the OSI model is 7 logical

Layer 3 is the network layer and utilises multiple common protocols to perform routing on the network. Protocols consist of the Internet Protocol (IP), packet sniffing and DoS attacks such as Ping floods and ICMP attacks. Because of their layer 3 nature, these types of attacks can be performed remotely over the Internet while layer 2 attacks primarily come from the internal LAN.

Which layer of the OSI reference model handles logical addressing (IP addresses) and routing traffic?

The TCP/IP protocols are the heart and soul of the Internet, and they describe the fundamental rules that govern all communications in the network. The original address system of the Internet is Internet Protocol version 4 (IPv4). The Internet Engineering Task Force (IETF) developed IPv6 to deal with the long-anticipated problem of IPv4 address exhaustion. However, IPv6 is not foreseen to supplant IPv4 instantaneously.

The internet matured in the 1970's as a result of the Transmission Control Protocol/Internet Protocol (TCP/IP), which is sill used today. It was adopted by the U.S. Department of Defense in 1980, and universally adopted in 1983. The usage of TCP/IP is what unites all elements of the net. Both public domain and commercial implementations of the roughly one hundred protocols of the TCP/IP protocol suite became available in the 1980's. During the early 1990's, Open Systems Interconnection (OSI) protocol implementations also became available by the end of 1991, the Internet has grown to include some 5,000 networks in over three dozen countries, serving over 700,000 host computers used be over 4,000,000 people. By December 1996, about 627,000 Internet domain names had been registered and now there are more than 30 million registered.

As the data packet moves from the upper to the lower layers, headers are _______.