The interesting thing is that layering of network protocols abstracts the implementation of one layer from the ones above and below it. Each layer must simply provide the interface as specified. This means we could actually have a TCP wrapper over any other hardware protocol (e.g. I2C, Rs-485). It will only be the implementation of the network access layer of TCP/IP that changes.

But of course, who needs the huge overheads of a TCP/IP when an I2C will be sufficient?? TCP/IP need only be used when connecting to the internet, in which case the hardware will almost always be an Ethernet controller or some modem.

kundi