Knowledge Base

As defined by the IEEE 802.3 Working Group, Auto-Negotiation is the process that Ethernet Devices use to identify and resolve the highest possible link between two devices. In simplified terms, Auto-Negotiation aids a user in finding the highest and most efficient operating speed for their system. Learn more about Auto-Negotiation in this overview paper written by Spencer Janelle, UNH-IOL Test Technician, CS, 2022.

Subclause 40.6.1.1.1 of the IEEE 802.3 Standard defines a test channel to be used in the testing of the jitter on the reference clock of 1000BASE-T devices. The channel consists of two short segments of 120m UTP Category 5 compliant cable, along with one (or two, if necessary) long (the exact length is dependent upon the attenuation of the entire channel) segment of 100m UTP Category 5 compliant cable. The channel is to meet or exceed the insertion loss, crosstalk, and return loss requirements as specified in clause 40.7. The objective of this paper is to outline and describe, in detail, the specifications defined in subclause 40.6.1.1.1 of the IEEE 802.3-2002 standard for the Jitter Test Channel, and observe the results of the testing of a completed test channel. Included are plots, outlining the characteristics of the constructed test channel, along with the limits of each specific test.

A brief tutorial describing the 1000BASE-X PCS and PMA sublayers that are defined in Clause 36 of the IEEE 802.3 Standard.

1000BASE-T PMA overview (location in the OSI stack, interface with PCS, interface with Auto-Negotiation, PAM-5 Encoding Scheme, PMA Sublayers Functionality and Functions, and PMA Electrical Specifications).

An introduction to the Clause 37 Auto-Negotiation Process.

GE 1000BASE-T, Physical Coding Sublayer (PCS) functional basics and overview.

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