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Re: Hi-Rise Building Fiber Suggestions


From: Bill Woodcock <woody () pch net>
Date: Wed, 26 Feb 2020 09:59:58 +0100

On 2/25/20 6:32 PM, Norman Jester wrote:
I’m in the process of choosing hardware
for a 30 story building. If anyone has experience with this I’d appreciate any tips.

There are two fiber pairs running up the building riser. I need to put a POE switch on each floor using this fiber.

The idea is to cut the fiber at each floor and insert a switch and daisy chain the switches together using one pair, 
and using the other pair as the failover side of the ring going back to the source so if one device fails it doesn’t 
take the whole string down.

The problem here is how many switches can be strung together and I would not try more than 3 to 5.

Yeah…  I’d regenerate every five L2 devices as well.  Which just means going up to L3 periodically.  Would it work for 
you to use the first pair for daisy-chaining switches on each floor that’s not a multiple of five, and then put the 
switches on the floors that are multiples of five into router mode, with a switch-group facing their own floor, but 
routed ports facing other floors?  Then use the second pair as an “express” lane between the exit, floor 10, and floor 
20, to keep L3 hop-sounds down and provide some redundancy?

                                -Bill

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