Marvell Semiconductor VCT Virtual Cable Tester Technology For Gigabit Networks White Paper 14 pages WP 2002 pdf/zip
To ease and facilitate the rapid deployment of Gigabit Ethernet to the desktop and throughout the enterprise network, Marvell has introduced an innovative new feature for its Alaska(R) family of Gigabit Ethernet Physical Layer (PHY) devices, called Virtual Cable Tester(TM) (VCT) technology. Built into the latest generation of Alaska PHYs, the VCT feature utilizes Time Domain Reflectometry (TDR) technology to remotely and non-evasively diagnose the quality and characteristics of the attached cable plant. Using this technology, the Alaska devices detect and report potential cabling issues such as cable opens, cable shorts or any impedance mismatch in the cable and accurately report – within one meter – the distance of the fault. Additionally, VCT technology will also detect pair swaps, pair polarity reversal and excessive pair skew.
Marvell’s VCT technology is truly revolutionary in that it enables the IT manager or end user to remotely diagnose the attached cable plant, quickly identifying the failing mechanism, and isolating the source of the problem. Essentially, VCT technology integrates, on a single chip, the functionality of a several thousanddollar cable meter system typically required by IT professionals to handle corporate network service and support issues. Moreover, with VCT technology integrated onto the Alaska PHYs, each device port can independently detect and report cabling issues without the need to unplug cables, connect cable testers and install loop-back modules at the far end.
Perhaps the best way to highlight the value of Marvell’s VCT technology is through an example. Consider a case where a corporation has been slowly upgrading their clients/PCs to Gigabit (10/100/1000 Mbps) connectivity and is now ready to upgrade the entire network with the purchase and installation of Gigabit switches. Upon installation of a Gigabit switch, the IT manager finds that all Gigabit ports are functioning with the exception of the fourth port. He/she then sees through the switch software interface a “pop-up” message that reads:
“Network connection has failed on Port 4. Pair 2 (typically pins 3 and 6, orange color) of your CAT 5 cable is discontinuous (“open”) approximately 68 meters from the switch.”
The IT manager is then able to make the repair to the cabling plant and all ports of the switch operate flawlessly at Gigabit speeds. The engine behind the above software pop-up message is Marvell’s VCT technology. In this example, due to integrated VCT technology, it is very likely that the switch systems manufacturer was spared the burden of receiving a phone call to their support line, or even a returned product. VCT technology is key to reducing the costly support issues experienced by manufacturers of networking equipment as well as improving customer satisfaction levels. Major systems manufacturers have estimated that by deploying VCT technology they would be able to eliminate 80% of received support phone calls.