Question : Fiber Optic Cables in server room

Hi,

1. I go to the server rooms,
2. And i see fiber optic cables (orange color) at the back of some servers; some are "marked" : Fiber Right and Fiber Left
3. These fiber optic cables some are connected to other servers,
4. And in those servers, also i see some CAT 5 cables,
5. My questions: i)What are  the functions of those fiber optic cables ?, ii) My understanding: The fiber optic cables function the same as CAT 5, but why they are used together there in the same servers
6. Any help ?

Tjie

Answer : Fiber Optic Cables in server room

Fibre Optic cabling is also used for SAN storage, usually plugging directly from the Server (via HBA card/interface) to the SAN Storage unit or from the Server(s) into a Fibre Switch, into which the SAN is also plugged into and gets high and reliable data rates (2GB-4GB with plans for 8GB in the next year).

Fiber in the DC can also be used for High security/reliability communications.  Fiber isn't subject to electromagnetic "noise" like Copper cabling is.  This noise comes from most anything electronic, but typically from Power Supplies and Florescent lighting within DataCenters and the copper cables have to be within 12 inches of the interference.
On the security side, Fiber is pretty hard to cut, splice and place a listening device inbetween the two endpoints (sniffing).  While Cat5/6 can be cut and spliced somewhat easily to place a listening device, it also can be "sniffed" by Induction: placing a special device alongside the cable and "listening in" on the traffic that's going over the wire.  Since communications over Fibre utilize light/laser pulses, they are practically impossible to "sniff" without cutting the Fibre - which the communications outage would be a Red Flag that something was wrong...

Hope this helps,
Scooter