Mismatched Cabling Components the Cause of Poor Network Performance

The research is part of Anixter's Levels Lab's (ALL) study of how cabling systems, transmitters and receivers interact and transfer data from the server to the PC. According to ALL, there is a direct correlation between impedance mismatches in network components and network inefficiency. Data traveling through the network is corrupted by changes in electrical resistance, or impedance. These changes occur at transition points where a patch cord plugs into information outlets/panels, or where horizontal cable is terminated.

Where impedance mismatches occur, portions of the data signal are reflected back to the original source. This reflection is known as return loss. Return loss creates significant problems that inhibit effective network operation. The signal that is reflected back toward its source imposes additional noise onto the cabling system — making it more difficult for the receiver to distinguish noise from signal.

"Current industry standards reflect minimum requirements, and therefore, ensure only minimal performance," Pete Lockhart (Anixter's Vice President of Technology and Product Design) advises. "For optimum network efficiency, go with cabling systems and compatible components that have been tested above the current requirements of your network." In short, make sure the cabling and components have matched impedance characteristics to avoid frame errors.

To receive a free copy of this Anixter Levels Lab Report, contact Anixter Inc. at 4711 Golf Road, Skokie, IL 60076; visit Anixter's web site at www.anixter.com; or call 1-800-ANIXTER.

Edited by: Jerry R. Borland, P.E.