Why is TCP/IP complex

[HarshaB]

My friend has recently entered into the world of networking. He started reading about OSI model and TCP/IP model. He asked me what's the difference between them and I was able to answer it easily. But the problem is that he yesterday also asked me why is TCP/IP is so complex and also why is it needed? If we have OSI model, then what is the use of TCP/IP model? Can't we just use OSI model rather than having TCP/IP model?

[Big Fish]

The Internet Protocol Suite (commonly known as TCP/IP) is the set of communications protocols used for the Internet and other similar networks. It is named from two of the most important protocols in it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were the first two networking protocols defined in this standard. The TCP/IP model consists of four layers, these are the Link Layer, the Internet Layer, the Transport Layer, and the Application Layer. TCP/IP offers multiple services like HTTP, FTP, e-mail, file sharing, remote support etc. Whereas OSI model doesn't serves this purposes.

Source: wikipedia

[Aleksandra]

The OSI model basically deals with how the data travels. The TCP/IP model was developed to create a Network of Networks (the "Internet"). The TCP/IP is more reliable protocol as compared to other network protocols. OSI "protocols" are dead, they can't be used for Internet. Whereas the TCP/IP "protocols" are alive and are more practical for use.

[Zachary]

TCP/IP is an industry standard suite of protocols that is designed for large networks consisting of network segments that are connected by routers. TCP/IP is the protocol that is used on the Internet. TCP/IP is the entire suite of protocols defined for use on private networks and the Internet. Because TCP/IP is the protocol of the Internet, it has evolved based on fundamental standards that have been created and adopted over more than 30 years. The future of TCP/IP is closely associated with the advances and administration of the Internet as additional standards continue to be developed.

Also see this: Networking Guide Part 3 - TCP/IP Fundamentals