Optics Guides

Do third-party optics void your switch warranty?

Properly coded optics come up on the switch exactly as the OEM module does — no special commands, no warning logs. Here is what that means for support and warranty.

BiDi and BX optics: more bandwidth on the fibre you already have

Two different technologies share the BiDi label. One halves your fibre count, the other gets 40G or 100G onto duplex fibre that was only ever meant for 10G.

MPO-12, MPO-16 and MPO-24: matching the trunk to the optic

Parallel optics need a ribbon trunk, and the fibre count, polarity and connector gender all have to line up. Most MPO problems are one of those three.

How to read a Cisco transceiver part number

Cisco part numbers are systematic once you know the pattern. Here is how to decode one, and what the suffixes actually change.

Active optical cables: reach without a transceiver budget

An AOC is a fibre link with the optics already attached and already matched. It covers the distances copper cannot, without the cost of two transceivers.

Direct attach cables: when copper beats optics

Inside a rack, a twinax cable is cheaper than two transceivers and a patch cord, draws no power and fails less. Here is where that stops being true.

Choosing an optical transceiver: speed, reach, fibre and connector

Four things decide which optic you need. Get them right and the part number almost picks itself.