OSI model

Layer 1

Physical layer.

bits, voltage, wire speed, pin-out, 1 and 0, DTE and DCE, topology,

• Data Terminal Equipment (DTE): device where the data begins or ends. unit that functions either as a source of or as a destination for binary digital data. Terminal, computer, printer.
• Data Circuit Terminating Equipment (DCE): device which transforms the signal if needed to another medium. unit that transmit or receives data in form of an analog or digital signal through a network. Modem, ISDN adapters, satellites and network interface cards. DCE converts that data from DTE to a form acceptable to transmission medium and sends converted signal to another DCE on network.

Layer 2

Sources

• https://www.geeksforgeeks.org/difference-between-dte-and-dce/