62.5 Versus 50 Micron Multi-Mode Fiber – 10GB and Beyond - Page 2
IDF Closet locations – If you have your IDFs less than 33 meters from the MDF (Main Distribution Frame), or core, location, then 10GB over multi-mode fiber works just fine using 62.5 micron fiber 10GBASE-SR. However, most IDFs are longer than 33 meters away from the core, prompting for another solution (which is addressed below in the “Bandwidth requirements” section) for any needs past 1GB.
Bandwidth requirements – If there is a need past 10GB for now or in the near future, I would take a long look at the cost of replacing the fiber for 50 micron fiber. However, even though many are shying away from 62.5 micron for 50 micron for 40GB and 100GB futures, existing networks can support 10GB (62.5 micron limit) further than the 33 meter standard (10GBASE-SR) with the presence of LRM or Long Range Multi-mode modules. These are readily available from network equipment manufacturers and can transmit 10GB/second over multi-mode fiber up to 220 meters (1310nm). NOTE – These modules can vary in cost from manufacturer to manufacturer. For example, initial cost analysis between 10GE-SR and 10GE-LRM had one manufacturer at 10% cost difference (LRM higher), while another had the LRM module 50% higher in cost over the SR module. For some large networks, this could add up considerably.
There are great deals of factors that one must consider for high traffic multi-mode fiber connections and more with those that have existing fiber infrastructures. However, evaluate current and immediate future needs with bandwidth requirements and costs and the picture will become clearer.