Similarities

Both TCP/IP and OSI have a layered design with each component being relatively independent of the others. TCP/IP does have some interdependence of the layers but generally retains separation.

Both systems were designed to be fault tolerant. Each has a system for evaluating the contents of datagrams and generating a Checksum. This means both systems can sense and correct errors in transport.

The two systems also create a barrier between the user/software and the actual technicalities of sending data through a network. This design also makes provision for libraries of functions that can be accessed by programmers to easily incorporate network access into their programs.

 

Differences

TCP/IP differs from OSI in several ways. OSI was created by the International Standards Organisation and therefore was clearly defined from the beginning. But the United States Department of Defence originally developed TCP/IP. The standard was then adopted by those who formed the first internetworks (that later became the Internet). They made subtle alterations to the protocol suite and the Department of Defence later updated their specification to be compatible with the defacto standard.

Another major difference is that TCP/IP does not extend all the way to the hardware and physical transfer of the data bits.