Protocol Layers

See also Protocol.

Part of the protocol will be the physical layer (fiber, copper). The protocol does everything, as it is specified. The problem is what if your boss wants to use fiber now? You would normally have to replace the whole protocol! To solve this problem they broke the larger protocol into smaller parts (ie: the physical layer) into layers.

This is very similar to the OS stack layers we talked about in Lecture 5 - Process Management. The nice thing here is that if you swap that layer (layer 1 in the figure above) then that doesn't change the whole protocol.

Notice that the layers themselves need to agree. If TCP on PC1 is sent, then TCP needs to be handled as that on PC2.