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CCNA 1 and 2 Companion Guide, Revised (Cisco Networking Academy Program) part 99

Cisco Networking Academy Program CCNA 1 and 2 Companion Guide, Revised part 99 is the Cisco approved textbook to use alongside version 3.1 of the Cisco Networking Academy Program CCNA 1 and CCNA 2 web-based courses. The topics covered provide you with the necessary knowledge to begin your preparation for the CCNA certification exam (640-801, or 640-821 and 640-811) and to enter the field of network administration. | appen_a.fm Page 949 Tuesday May 20 2003 4 54 PM Finish Phase 949 Link and Channel Testing Two methods are used when testing the channel test and the link test. The channel test goes truly end-to-end from the workstation or telephone to the device in the telecommunications room TR . The channel test measures all of the cable and patch cords including the line cord from the jack to the user equipment and the patch cord from the patch panel to the communications equipment. Alternatively the link test tests only the cable from the wall back to the patch panel. There are two types of link tests the basic link test and the permanent link test. The basic link test allows no connectors but the point of measurement starts near the field tester and ends near the field tester remote unit at the other end of the link. The permanent link test excludes the cable portions of the field test units but includes the mated connection where the cable is connected to the adapter cable at each end see Figure A-48 . Figure A-48 Permanent Link Test Outlet Patch Panel Consolidation Point The permanent link test also allows for a consolidation point which is desirable for open-office cabling installations and is therefore more practical. The only accepted test is the permanent link test. The channel test officially has been eliminated by TIA EIA-568-B.1. Certification Tips How test results are interpreted is just as important as detecting problems. The best way to learn how to interpret test results is to use test equipment on known good wires and circuits. This will give the installer a knowledge base of how to properly use test equipment and how the test results should appear when the circuits are functioning properly. To gain experience with troubleshooting and problem identification create cables with specific problems. Observe how testers react to these problems. Practice identifying these problems based on the results of testers by randomly choosing cables. It will be worth spending .