What are the drawbacks of OSI model and why TCP implemented instead of OSI?

OSI is an overblown, bloated, everything-to-everybody protocol that does nothing particularly well.  TCP/IP, on the other hand, has been designed to work from day one. It was designed, implemented, redesigned, and refined in the context of a real network environment, not a bureaucratic vacuum of people who are more concerned with stuffing every possible feature into a protocol than making a protocol that is implementable in a practical sense. On top of that, the TCP/IP specifications are free.  ISO charges a hefty fee to anyone who would dare read about its protocol.

1. OSI provides layer functioning and also defines functions of all the layers. 1. TCP/IP model is more based on protocols and protocols are not flexible with other layers. 2. In OSI model the transport layer guarantees the delivery of packets 2. In TCP/IP model the transport layer does not guarantees delivery of packets. 3. Follows horizontal approach 3. Follows vertical approach. 4. OSI model has a separate presentation layer 4. TCP/IP does not have a separate presentation layer 5. OSI is a general model. 5. TCP/IP model cannot be used in any other application. 6. Network layer of OSI model provide both connection oriented and connectionless service. 6. The Network layer in TCP/IP model provides connectionless service. 7. OSI model has a problem of fitting the protocols in the model 7. TCP/IP model does not fit any protocol 8. Protocols are hidden in OSI model and are easily replaced as the technology changes. 8. In TCP/IP replacing protocol is not easy. 9. OSI model defines services, interfaces and protocols very clearly and makes clear distinction between them. 9. In TCP/IP it is not clearly separated its services, interfaces and protocols. 10. It has 7 layers 10. It has 4 layers

 

OSI model drawbacks :

-Many applications do not require/need the data integrity, which is provided by OSI-model.

-In order to fast set up OSI requires agreement b/w three-parties: users & service provider.

-Complex.

-This model is not adapted at all to telecommunication applications on computer.

 

Why TCP/IP model:

• It can be used to establish/set up connection b/w different types of computers.
• It operates/works independently of the operating system.
• It support for a number of routing-protocols.
• It enables the internetworking between the organizations.
• It has a scalable, client-server architecture.

 

 

 

drawbacks :

• Many applications do not require/need the data integrity, which is provided by OSI-model.
• In order to fast set up OSI requires agreement b/w three-parties: users & service provider.
• Complex.
• This model is not adapted at all to telecommunication applications on computer.

OSI is an overblown, bloated, everything-to-everybody protocol that does nothing particularly well.  TCP/IP, on the other hand, has been designed to work from day one. It was designed, implemented, redesigned, and refined in the context of a real network environment, not a bureaucratic vacuum of people who are more concerned with stuffing every possible feature into a protocol than making a protocol that is implementable in a practical sense.

 

On top of that, the TCP/IP specifications are free.  ISO charges a hefty fee to anyone who would dare read about its protocol.

iso model are 7 type different layers to developing the communication. it will taken much time to produce the data into source to destination, and identify the destination is also take much time. because of  this are wired based system.

 

once the application layer completed means automatically the second stage presentation layer can work that  continues into total 7 layer each and every layer can be must and should verified to delivered the destination.

 

connection are wire based it will take risk.

 

but tcp can be implemented into direct connection of host to internet to the destination. the tcp are contains only 4 layers only .

 

it will work wireless connection also easy way to connecting to the source to destination using ip address of destination device.

Many applications don't need the data integrity provided by this mode as well as it's complexity. The TCP/IP model separates the networking functions into distinct layers & each layer performs a specific function.

Drawbacks of OSI Model 

 

1. Many LANs are powerful (high speed) and has low error rates, many applications do not need the data integrity provided by OSI.

 

2. Many LAN applications need very fast setup with each other but the connection mode transfer in OSI requires an agreement between 3 parties, users and the service provider, hence it is slow.

 

3. The OSI model is too complex. The gap between the concrete use (implementation) and the model is sometimes significant. Indeed, few programs can use or wrongly use the 7 layers of the model: the session and presentation layers are hardly used and on contrary the data link and network layers are often split into several sub-layers, since they are pretty complex. The OSI model is in fact too complex to be effectively and properly implemented. The committee that wrote the standard even had to leave aside some technical points, like security and coding, so much it was delicate to preserve a well defined role to each layer completed with these extra technical points. This model is also redundant (the flow control and the error control appear in most layers). At the implementation level, TCP/IP is much more optimized and effective.

 

4. OSI model is not adapted at all to telecommunication applications on computer. Some choices are in disagreement with the way computers and software communicate. The standard actually uses "system interruptions" to report events, and with high level programming languages, that is not very realizable.

5. Due to the complexity of the model, the first implementations were pretty heavy and slow.

 

Conversely, the first implementation of TCP/IP in the Unix system of the Berkeley University (BSD) was free and relatively effective. Historically, people thus had a natural tendency to use TCP/IP.

 

Why is TCP implemented instead of OSI?

 

Because OSI is largely unimplementable.  It was a wet dream of academics who never ran or wrote code for a production network.

OSI is an overblown, bloated, everything-to-everybody protocol that does nothing particularly well.  TCP/IP, on the other hand, has been designed to work from day one. It was designed, implemented, redesigned, and refined in the context of a real network environment, not a bureaucratic vacuum of people who are more concerned with stuffing every possible feature into a protocol than making a protocol that is implementable in a practical sense. On top of that, the TCP/IP specifications are free.  ISO charges a hefty fee to anyone who would dare read about its protocol.

 

 

 

There are a number of reasons for the success of the TCP/IP protocols over OSI:

TCP/IP protocols were specified, and enjoyed extensive use, prior to ISO standardization of alternative protocols. Thus, organizations in the 1980s with an immediate need were faced with the choice of waiting for the always promised, never-delivered complete OSI package, and the up-and-running, plug-and-play TCP/IP suite. Once the obvious choice of TCP/IP was made, the cost and technical risks of migrating from an installed base inhibited OSI acceptance.

The TCP/IP protocols were initially developed as a U.S. military research effort funded by the Department of Defense (DOD). Although DOD, like the rest of the U.S. government, was committed to international standards, DOD had immediate operational needs that could not be met during the 1980s and early 1990s by off-the-shelf OSI-based products. Accordingly, DOD mandated the use of TCP/IP protocols for virtually all software purchases. Because DOD is the largest consumer of software products in the world, this policy created an enormous market, encouraging vendors to develop TCP/IP based products.

The Internet is built on the foundation of the TCP/IP suite. The dramatic growth of the Internet, and especially the World Wide Web, has cemented the victory of TCP/IP over OSI.

 

Two basic points summarily are:

The cost involved in designing TCP/IP suite is comparatively less.

TCP/IP as a basic foundation it is easy to build Internet Systems.