Introduction Main section Concenntrator hub conclusion

Conclusion
The OSI protocol suite that was specified as part of the OSI project was considered by many as too complicated and inefficient, and to a large extent unimplementable.^[37] Taking the "forklift upgrade" approach to networking, it specified eliminating all existing networking protocols and replacing them at all layers of the stack. This made implementation difficult and was resisted by many vendors and users with significant investments in other network technologies. In addition, the protocols included so many optional features that many vendors' implementations were not interoperable.^[37]
Although the OSI model is often still referenced, the Internet protocol suite has become the standard for networking. TCP/IP's pragmatic approach to computer networking and to independent implementations of simplified protocols made it a practical methodology.^[37] Some protocols and specifications in the OSI stack remain in use, one example being IS-IS, which was specified for OSI as ISO/IEC 10589:2002 and adapted for Internet use with TCP/IP as RFC 1142

References:

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   ^ Jump up to:^a b Andrew L. Russell (30 July 2013). "OSI: The Internet That Wasn't". IEEE Spectrum. Vol. 50 no. 8.
   
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   ^ "OSI The Internet That Wasn't". IEEE Spectrum. March 2017.
   
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   ^ Sunshine, Carl A. (1989). Computer Network Architectures and Protocols. Springer Science & Business Media. p. 35. ISBN 978-1-4613-0809-6.
   
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