TCP and OSI models comparison Essay

TCP and OSI models comparisonTCP/IP has become a very familiar jargon even to non-techies these days. This is due to the wide use of Internet even in the remotest of places around the world.

TCP/IP is a protocol or in simple terms a language / media of communication between computers in a network. TCP/IP is the acronym for Transaction Control Protocol / Internet Protocol. This model consists of four levels which are Application Layer, Internet Layer, Network Interface Layer and the Transport Layer. Application layer breaks the data into different small packets containing information regarding the sender, receiver and code for checking the authenticity of the packet along with the data.

Transport Layer manages the session connected while Internet Layer re-packs the packets into datagram which are transmitted across different networks and Network Interface Layer deals with the actual transmission of data (TCP/IP History. University of East London).The OSI (Open Systems Interconnection) model provides a standard for networking models. Over the time the OSI model has become a base for various networking protocols. OSI consists of seven layers namely the Application Layer, Presentation Layer, Session Layer, Transport Layer, Network Layer, Data Link Layer, and Physical Layer. Application Layer is the seventh layer which is open to the end user.

Presentation Layer prepares the data to be sent over the network by encryption. Session Layer, as the name suggests, manages the session of the connection. Transport Layer is responsible for consistency of data transmitted. Network layer manages the route for transmission. Data Link Layer handles the coding and decoding of data packets. Physical layer manages the material network connection to a computer (OSI History. University of East London).

The major similarities between TCP & OSI models are that they are layered and transmit data as packets. Each TCP/IP layer either matches directly to an OSI layer or it is a combination of two or more OSI layers in functionality. The Application, Presentation and Session layers of OSI Model corresponds to the Application layer in TCP/IP. The Transport layer of ISO corresponds to the Transport layer of TCP/IP. Similarly the Network Layer of ISO corresponds to the Network / Internet Layer of TCP/IP. Data Link layer and Physical layer of ISO corresponds to the Network Interface layer of TCP/IP. Thus we may conclude that both models are very much related to each other. The difference between TCP and OSI models are as follows; the main difference between TCP and OSI is that TCP/IP model is a combination of various protocols while OSI is a theoretical model.

The TCP model is comprised of 4 layers while the OSI model has 7 layers (Comparison of OSI and TCP/IP models).The status of network (whether connection-oriented or connection-less) is very vague in a TCP/IP model whereas it is more precise in an ISO model (Bruno. 2002 p.

268).Though the basic role of the layers is similar in both TCP and OSI, they achieve the role in different ways, i.e., their approach is different. One main aspect of networking is the consistency of data transmitted. Data consistency is checked in each layer in the OSI model whereas in TCP/IP data checking is done only in the Transport layer. Network handling is done differently in a TCP model when compared to an OSI model. In TCP/IP, the hosts are intelligent, which means they are capable of managing themselves in a network whereas when OSI implemented it has limited capability to handle network independently.

OSI models are recognized as a standard by the ISO whereas TCP/IP has become popular due to its widespread usage. OSI is more generic whereas TCP/IP relates more to Internet. The OSI model came much before the protocols were developed. Hence it is easier to adapt to technology changes. OSI model is very complex and expensive to implement. TCP/IP model is relatively simple and stronger.

OSI model is less common due to its complexity whereas TCP/IP model is supported by almost all operating systems and hardware. OSI model has more academic purposes whereas TCP/IP’s practical implementation is widely available which forms the foundation for Internet (Revise Computing. Comparison and Contrast between the OSI and TCP/IP model).

On the whole, TCP/IP and ISO models share many similarities while maintaining their distinctiveness.ReferenceBruno, A. 2002 CCIE Routing and Switching Exam Certification Guide: Routing and     Switching.

Indianapolis: Cisco Press.Comparison of OSI and TCP/IP models Available:     http://homepages.uel.ac.

uk/u9703493/comparison.htm. Accessed on October 2, 2008OSI History. University of East London Available: http://homepages.uel.

ac.uk/u9703493/osi-history.htm. Accessed on October 2, 2008Revise computing.

Comparison and Contrast between the OSI and TCP/IP model. Available:     http://www.revisecomputing.co.uk/h_revision/resources/h_cn_osi.ppt. Accessed on     October 2, 2008TCP/IP History.

University of East London Available:     http://homepages.uel.ac.uk/u9703493/TCP-history.

htm. Accessed on October 2, 2008