A packet of data contains a packet header, payload, and trailer. The packet header includes the destination address, packet number, and originator’s address. Data is broken down into packets. Each packet could take a different route. A router controls the route a packet takes. Packets may arrive out of order. Once the last packet has arrived, packets are reordered. Including: serial, parallel, simplex, half-duplex, full-duplex. Including the advantages and disadvantages of each method. Including the benefits and drawbacks of the interface.

Errors can occur during data transmission due to interference, e.g., data loss, data gain and data change. Including parity byte and parity block check. Including the use of positive/negative acknowledgements and timeout.