In this article we will discuss Duplex Operation, will make brief discussion on Duplex Operation, In last article we discuss about Types of Malware.
In data communications, duplex refers to the direction of data transmission between two devices. If the communications are restricted to the exchange of data in one direction at a time, this connection is called half-duplex. Full-duplex allows the sending and receiving of data to happen simultaneously.
For best communication performance, two connected Ethernet network interfaces must operate in the same duplex mode to avoid inefficiency and latency on the link.
Ethernet autonegotiation was designed to facilitate configuration, minimize problems and maximize link performance. The connected devices first announce their supported capabilities and then choose the highest performance mode supported by both ends. For example, the switch and router in in the figure successfully autonegotiated full-duplex mode.
If one of the two connected devices is operating in full-duplex and the other is operating in half-duplex, a duplex mismatch occurs. While data communication will occur through a link with a duplex mismatch, link performance will be very poor. Duplex mismatch may be caused by incorrect manual configuration, which is manually setting the two connected devices to different duplex modes. Duplex mismatch can also occur by connecting a device performing auto-negotiation to another that is manually set to full-duplex. Although rare, duplex mismatch can also occur due to failed autonegotiation.