Security And The OSI Model Essay

A: OSI stands for Open System Interconnection. The main aim of the OSI layer is to implement protocols of a networking framework.

Layer 3: Network - The way that the data will be sent to the recipient device is determined in this layer. Logical protocols, routing and addressing are handled here.

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

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

The OSI Model is a model is used to define how data is theoretically passed on a network. Each layer is responsible and has its own duties for a network. The name of layer 3 in the OSI is the Network Layer. This layer is responsible for creating the paths for the transmission of data across the network. This layer provides routing and switching capabilities, as well as, internetworking, congestion control, and packet sequencing (Beal, 1999).

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

To reduce the risk of these types of attacks, routers should be hardened, packet filtering controls should be used and routing information should be controlled.

2. The OSI model is not directly implemented in networking and often the distinction between the layers will blur in implementation. Why does it endure despite these

4. Transport protocols resemble those you studied in Data Link Layer since both will have to deal with error control, sequencing, flow control etc. Still the two differ significantly. How? elaborate with at least 4 differences.

Each layer has a specific function and the layers work together to allow an application to send data over a computer network without really specifying the exact protocols and/or physical wiring within each layer. In line with the figure above, when the first CEO sends an email message to the second CEO, email ‘application worker’ firstly prompts the first CEO to enter a message and specify that the receiver is the second CEO. The application worker then creates the necessary data package with message contents and the destination email address and send s this to a ‘transport worker’. The transport worker provides transport integrity. The transport worker may establish a connection with the receiver (second CEO); monitor the overall

The application layer: this layer allows different applications to communicate with each other’s. In order to exchange different data over the network connection, the protocols included in this layer set up the standards such as DNS, HTTP, FTP. The data coded in this layer will be encapsulated to transport layer for further packing.

The OSI data model originated in 1977 and this model contained the original seven layer protocol. The model has since been modified to be used with the changing protocols of the network whilst keeping the seven layers. The seven layer OSI model has been able to cope with the updates but there are duplications of operations which creates a redundancy in the model.

Abstract-The IP multimedia subsystem (IMS) is a Next Generation Network (NGN) that integrates wireless, wireline and internet technologies. IMS enables the convergence of voice, data, and multimedia services such as Voice over IP (VoIP), Video over IP, push-to-talk, presence or instant messaging services. IMS is almost independent of the access technology and uses a number of protocols such as HTTP and SMTP while the most important one is called SIP or session Initiation Protocol. At parallel this open based emerging technology has security challenges from multiple communication protocols like IP, SIP and RTP etc. Because of the nature of the IMS (IP based), these networks will inherit most of the security threats that these protocols are

In this report, the OSI and TCP/IP models will be compared after going through a brief history and how the models were made. The report will bring the reader a greater understanding about the OSI and TCP model. The model shows the different layers for example for the OSI model it has the following layers: Application layer, Presentation layer, Session layer, Transport layer, Network layer, Data-Link layer and Physical layer. The similarities in the TCP model would be: the Application layer and the Transport layer. This is then compared for the differences to see which models layer has, that is different to the other.