Data Terminating Equipment or Data Circuit-Terminating Equipment speeds
Data Terminating Equipment (DTE) and Data Communication Equipment (DCE) are used to describe two different hardware groups.
The term DTE is used primarily for those devices that display user information. It also includes any devices that store or generate data for the user. The system units, terminals, and printers all fall into the DTE category.
DCE includes any device which can be used to gain access to a system over telecommunication lines. The most common forms of DCEs are modems and multiplexers.
With serial communication on this operating system involving modems, as pictured in the above illustration, there are three major considerations:
- DTE interface speed (server to modem). This is the speed the server communicates to the modem.
- DCE interface speed (modem to server) sometimes called the "serial port interface speed." This is the speed at which the modem communicates to the server.
- Connection speed (modem to modem). This is the speed at which a modem communicates (or talks) to another modem.
Most modern, high-speed modems allow the DCE interface speed to be different than the connection speed. This allows the DTE speed to be locked at a single baud rate while allowing the connection speed to fluctuate, up or down as needed, for proper communication between modems.
Modern high-speed modems hold the data to be transmitted to the server in a buffer and send it when the system can accept it. They can also hold data to be transmitted to the other modem in a buffer and send it as the remote is able to accept it. This kind of data transmission requires the modem and the server to engage in flow control.