Network topology and fibre

country_lad

Hello all,
I am looking at various networks and how network topologies relate to the fibre network i.e. estimating the type and quantity of fibre optic cable required. I've done up the following simple schematic which shows a central core server which in turn feeds a fibre ring loop of 6 switches to create redundancy. Each local switch would then provide communications links at each site i.e. IP CCTV etc. They are also daisy chained as you can see. The fibre is the black line whilst the blue lines are local LAN/CATV or whatever at each site.

So if I was to build this network would it be sufficient to have a single 4 core singlemode cable to create the loop i.e. Each connection between switches would only require 2 cores (tx and rx)?. 4 cores seems overly little considering such a network could be expanded in a similar fashion to add in multiple of switches.

roast

No schematic there?

country_lad

Updated now with schematic

roast

What speed do you plan to run the links?
Judging from the above diagram, I'm assuming you want to use fibres 1/2 to deliver data and 3/4 for Video. Or are you using the extra pair for redundancy?

If it's the former, then realistically you wouldn't need the second pair if you just use 10Gb links. You could have two VLANs to separate the video and data networks.
If its for rendundancy then it might just be overkill as a ring using RSTP would be plenty of redundancy for most uses.

ArielAtom

Why singlemode? What are your distances between sites. I would design a star as against a ring offering better resilience if diverse ducts are available .

cherrytaz

Singlemode I assume would be used dependent on the distance required?