Being a filer admin entails speaking with datacenter engineers. Hopefully this will help with some of the acronynms.
Connecting to TOR switches
Transceivers modules
As seen on the diagram above, each module may implement a different ethernet physical layer. This decoupling allows switches and other networked devices to support both copper and fiber.
What are the “modes” in multimode fiber ?
Contrary to my initial belief, multimode has NOT higher bandwidth. It is just cheaper.
A mode refers to the angle of incident of the light source into the fiber. Not to be confused wavelength division multiplexing. The reason to have multimode is cheaper manufacturing : light sources need to be less precise and fiber cores have a higher radius compared to single mode.
AFAIK, mode division multiplexing is not used to increase bandwidth. On the contrary multimode fibers are limited in range and frequency due to intermodal dispertion.
Patch panel connections
Do NOT confuse fiber polarity with light polarisation !
Dual LC, as the name implies, has 2 fibers for full duplex. Problemo : how do you make sure RX/TX fibers go from device to device correctly ?
This problem gets complicated when connecting devices across racks via patch panels. There are different connectivity methods, below is just one of them.
