Impedance Matching. Throughput SOLUTIONS NETWORK PERFORMANCE. Only the TrueNet Impedance-matched System Protects Network Performance

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1 Throughput SOLUTIONS Impedance Matching Protects NETWORK PERFORMANCE Original 100BaseT MLT-3 signal transmission Only the TrueNet Impedance-matched System Protects Network Performance Networks for today s business environment need to be fast and efficient. But implementing the current breed of Fast Ethernet networks is a big commitment. It takes time, money, and considerable effort to get your high-speed network up-and-running smoothly and reliably. Once these commitments have been made, and your network has been installed, how do you know if it s performing up to its potential? Does achieving link light mean your network is running efficiently? Unfortunately, Ethernet is not an on-off proposition. A successful link can be a real throughput-wrecker if it is causing data loss. This begs the question: Are you really getting all the network throughput you paid for?...all the throughput you need? How can you tell? Problematic transmission of a live 100BaseT signal due to impedance mismatch. If your network components simply adhere to Category 5 standards, your link light may be on, but it is possible that you are losing data (which would look like the corrupted data signal, shown above).

2 Network Throughput Problems SOLUTIONS Factors Affecting Network Throughput To safeguard the integrity of your data, keep in mind the following: Electrical characteristics such as impedance, ACR, and delay skew are, of course, important. However, the true test of any structured wiring plan is how well the original data is retained as it travels within the physical layer. Common inconsistencies in structured cabling, such as impedance mismatches, cause data errors. This happens when cables containing pairs that vary in impedance are attached to patch cables, or connectors, with a non-matching impedance. This impedance mismatch causes instability across the frequency spectrum. How the TrueNet System Protects Network Throughput Krone/Prestolite have solved network re-transmission problems by designing a structured cabling system to impedance-matching standards that are more rigorous than the current standards, and include IEEE system guidelines not found in structured cabling standards. These TrueNet C5eT and C6T solutions incorporate tuned components including: patch cables, jacks, horizontal cables and patch panels. Total system tuning protects data integrity and enhances network throughput. Electrical instability can hurt data integrity. This potentially causes data re-transmission to occur. Re-transmissions cause a reduction in Ethernet throughput.

3 Throughput SOLUTIONS Impedance Matching New Research Proves You Can Protect Network Throughput Until recently, the only testing equipment available for verifying network performance were relatively unsophisticated TSB Level II hand-held devices, and network testing software tools which did not address the physical layer. The TSB testers could only test a passive environment (the cabling plant with no network actually operating). Software tools typically address higher-level functions, and cannot adequately diagnose physical layer issues. Neither type of tool is able to diagnose interrelated problems which could degrade overall network performance. Today, there is a whole new generation of testing equipment which looks at the entire network while it s under operation. Using this tool, Prestolite has developed new testing methodologies which have uncovered some surprising findings regarding network throughput. The new tests show that the degree to which all the network components are impedance matched has a great effect on the throughput of the network. Even when all components meet Category 5 specifications, if they re not impedance matched (component to component), the network may not operate up to its true potential. Transmission Problems Occur When There is an Impedance Mismatch Network designers have always known that impedance is important that s the reason for the long-established standard impedance value of 100 (±15) ohms for network components. But the new tests show that this acceptable range may be too great. USING NEW TEST EQUIPMENT AND NEW TEST METHODOLOGIES, PRESTOLITE HAS UNCOVERED SOME SURPRISING FINDINGS REGARDING NETWORK THROUGHPUT. We also know that transmission problems are more likely to occur at junction points. Even greater transmission problems are likely, however, if we use components with mismatched impedances. The illustration, below, depicts this impedance mismatched phenomena showing how data packets can be reflected and some data lost at the point where the connector mates a horizontal cable with a patch cord. Mismatched Channel Acceptable Impedance Range 115Ω 110Ω 105Ω 100Ω 95Ω 90Ω 85Ω NIC Patch Cord Energy is reflected at the mismatch, causing some frame data to be reflected and lost. Connection Point Impedance mismatch (107Ω to 97Ω) at Connection Point Damaged frames must be re-transmitted, slowing network performance Horizontal Cable Key Ethernet Frame Mismatched Channel TrueNet Impedance Range 115Ω 110Ω 105Ω 100Ω 95Ω 90Ω 85Ω NIC Matched components allow signal to travel with minimum reflection and loss, minimizing re-transmission and enhancing efficiency. Patch Cord Connection Point TrueNet Matched Channel Horizontal Cable Key Ethernet Frame TrueNet Channel Impedancematched components allow your data to travel throughout the network with minimum reflections and loss.

4 To illustrate the problems caused when mismatched cables are used, an experiment was set up with a horizontal cable and a patch cable which have slightly different impedances. It s important to note that each cable passed the Category 5 certification and the link light was on. The graph (below, left) depicts the impedance over distance in a channel consisting of patch cords, connectors, and horizontal cable. It s very easy to see the spike at three meters where the horizontal cable and the patch cable are connected: In fact, the pair-to-pair impedances actually reverse on the pairs shown in the close-up! The graph (below, right) shows the effects of the impedance mismatch in the frequency domain. There are wild swings in the impedance curve, the worst of which happen at frequencies most important to 10/100MB/s operation. These impedance swings result in a corrupted data signal and data errors. The network electronics respond to these Maximum Percent Data of Re-transmissions Rate 0% 100MB/s 1% 20MB/s 2% 4MB/s 3% 0.8MB/s 4% 0.16MB/s 5% 0.032MB/s Effect of data re-transmission on network throughput 80% degradation from only 1% re-transmission. errors by requesting re-transmissions of the data. These re-transmissions dramatically reduce the throughput of the network. Even a 1% rate of data re-transmission can slow a 100MB/s Ethernet network down to just 20MB/s. The bottom line is this: When network components are not impedance matched, the network slows down. Throughput suffers and you may not even know it, because the link lights are on. Impedance vs. Distance Impedance vs. Frequency Pair 1 Pair 2 Pair 3 Pair Distance (Meters) Frequency (MHz) Impedance mismatch at a horizontal and patch cable connection results in wide frequency variations and inconsistencies.

5 Introducing the TrueNet System Impedance vs. Distance Impedance vs. Frequency Pair 1 Pair 2 Pair 3 Pair Pair 1 Pair 2 Pair 3 Pair Distance (Meters) Frequency (MHz) Impedance-matched TrueNet channel shows the results of a 100BaseT transmission with excellent consistency and reduced signal variation. Only the TrueNet System Addresses The Impedance Mismatch Problem The examples of mismatched components shown on the previous pages are more common than one might think. That s largely because most users don t test their structured cabling as a channel. Instead, it is tested as a link by the cable installer (channel minus patch cables), and the user (or the integrator) must purchase the patch cables. If the patch cables don t match the horizontal cable electrically, network throughput can be impeded. TrueNet cable products called TrueMatch which maintains this high degree of impedance matching. Each TrueMatch pair is specifically tuned to conform to 100 (±3) ohms differential impedance. To complement the TrueMatch technology, Krone components are tuned to maximize the benefits of impedance matching in the cable. The results of the TrueNet cabling philosophy can be seen in the two graphs (top). They show a smooth impedance-versus-distance and impedance-versus-frequency characteristic. The benefits to your network are fewer errors, and preserved throughput performance. AS A NETWORK USER, YOUR BEST ASSURANCE OF AN IMPEDANCE-MATCHED INSTALLATION IS TO SPECIFY TRUENET COMPONENTS: JACKS, HORIZONTAL CABLE, PATCH PANELS AND PATCH CORDS. Based on our research, a patch cable to horizontal cable differential impedance tolerance of 100 (±3) ohms ensures that data errors and re-transmissions will be kept to a minimum, to maximize network throughput. As a result, Prestolite developed a patent-pending technology in our Only from Krone and Prestolite Wire, Your Network Cable Experts Krone/Prestolite are the only cabling system manufacturers looking at the real-world problem of active network throughput. The key is tight impedance matching to standards more stringent than anyone would have imagined. The result is the TrueNet system, designed from the ground up to protect the performance or your network.

6 Your NETWORK CABLE EXPERTS KRONE, INC South Tucson Way Englewood, CO Phone: Fax: Customer Service Hotline: KRONE ( ) Fax: URL: PRESTOLITE WIRE CORPORATION 200 Galleria Officentre, Suite 200 CS#5022 Southfield, MI Phone: Fax: Customer Service Hotline: Phone: Fax: URL: Copyright July 1999, Prestolite Wire Corporation