光纤骨干与园区互联

Glass fiber doesn't conduct electricity, so lightning, motor noise and ground-potential differences between buildings don't affect it. Inside buildings we use OM3/OM4 multimode (10GBASE-SR reaches 300 m on OM3 and 400 m on OM4). Between buildings, across plants and at mines where distances are in kilometres, we use OS2 single-mode.

For any new link between buildings we recommend OS2 almost every time. The cable costs about the same and it has far more headroom for future speeds.

Cable for the route

• Armored: direct burial or anywhere with rats. Rodents chewing fiber is real, especially in warehouses and food plants.
• ADSS: aerial pole runs without a steel messenger.
• HDPE duct: routes you'll add to later. Lay the duct once and blow more cable in when needed.

Every joint is fusion-spliced in a sealed closure and tested with an OTDR and power meter.

Lay spare cores

Labour and trenching are most of the cost, not the cable. Twelve cores instead of four costs little more and saves digging twice. Systems that can't stop should have a second, physically separate ring path, because excavators and trucks hitting poles don't book ahead.