Chapter 2: Overview
What is LAN Performance Verification?
LAN performance verification means that a UTP cable passed a prescribed battery of tests and is therefore not likely to cause problems later. The LPV has two levels of verification:
LPV Level 1: Performed with the Main Unit and the Remote Probe, Level 1 tests the cable for length; opens, shorts, split pairs and distance to the fault; wire map (displays cable wiring); NEXT and FEXT (crosstalk tests); propagation delay (time to transit cable); skew (time delay between pairs); cable category (CAT3, 5, 5e, 6); and speed projection (10, 100, 1000 Mbps).
LPV Level 2: Includes all Level 1 tests plus it takes advantage of a real live data source (hub, switch, or PC) to test for attenuation and device type. An LPV Level 2 test verifies speed of both the cable and the LAN device.
Networks are installed in steps. First, cables are installed. Then hubs, switches, and PCs follow. Cables and network interfaces are known as the physical layer. The higher software layers provide addressing, file transfers. etc. If the physical layer does not work, the communications layers (software) will not work. Debugging cables, ports, and network software together is
What is the best time to LAN Performance Vertify a cable?
The best time to vertify a cable is when the installer is still readily available to repair any faults that are found. Installers should verify before they leave, so that they will not lose money by having to return to a job site to do warranty repairs. Network professionals should also verify before the warranty period expires.
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