Gigabit Copper General Info
Gigabit over Copper (1000Base-T), described in the 802.3ab specification, provides for Ethernet networks running at 1000 Megabits (Gigabit) using standard Category 5 wiring. Unlike the Fiber standard (802.3z), the length limits specified are maximum distances. The Fiber standard specified minimum distances for products to be considered "within spec".
Standard Category 5 wiring has a distance limitation of 100 Meters. There are two caveats for using Category 5 cabling for 1000Base-T:
- The cable plant should be Category 5 certified. (This is almost a must.)
- All four pairs must be available for use. No split-pair wiring is allowed.
Other than that, everything else follows the normal Category 5 wiring rules for 10/100 Mb/s Ethernet. Here's a quick review for standard cable plant implementations:
- Use a three-meter patch cord from the active component to the patch panel.
- Use a three-meter cross-connect patch cord between a maximum of two patch panels in the wiring closet.
- Use a 90-meter horizontal cable run from the patch panel to the wall outlet.
- Use a three-meter patch cord.
- Use no more than a 1/2 inch of cable jacket removed at the punch down and wall outlet.
You'll notice that the total distance adds up to 99 meters. The extra meter is there in case you need it (for a total of 100 meters) from end-to-end.