Definition[]
A protocol stack is the ordered set of protocol types used in communications networks. At the lowest level, the protocol defines the physical interaction of the network components; at the highest level, the protocol defines the applications interacting with users.
Overview[]
A protocol stack is designed so that protocols in each layer of the stack are substitutable for each other without affecting protocols higher up the stack.
The seven-layer International Standards Organization (ISO)/Open Systems Interconnection (OSI) Technical Reference Model (TRM) is set forth below.