Using Ethernet Auto-negotiation protocol to avoid slow network connectivity or application time outs

Feb. 18, 2010
In this white paper N-TRON discusses the details of Auto-negotiation protocol and how to properly configure Auto-negotiation settings for maximum performance of industrial Ethernet networks.
In today's world of computer networks auto-negotiation is an important plug-and-play technology. Auto-negotiation as an algorithm was defined by Section 28 of the IEEE 802.3 standard and first introduced in 1997 as part of the IEEE 802.3u standard on Fast Ethernet. Auto-negotiation was designed to be backward compatible with the original Ethernet networking standards as well. Auto-negotiation was further enhanced in 1999 by the IEEE standard 802.3ab with the introduction of Gigabit Ethernet. Auto-negotiation is best defined as the mutual agreement by two network devices sharing a wire on the speed, duplex, and controls to govern the use of that wire. As a protocol auto-negotiation exists strictly at the PHY (physical) layer of the OSI (Open System Interconnection Reference Model) and is implemented by software, hardware, or a mixture of both. Specifically this white paper will detail how the protocol negotiates speed, duplex, Auto-MDIX (cable termination), and flow control.Download white paper