Fibre termination and configuration

aleph.haz · ‎05-09-2013

Hi,

I'm in the process of designing our new network. We have established our current network in unit 1, and we now have a new building with virtually nothing in it - unit 2. We plan on having some fibre cables installed between these two buildings. This is the first network I've designed, and while I am happy with concepts like routing, VLANs and various layers of the OSI model, the least familiar to me is layer 1.

I've been told that providers normally terminate the fibre using a patch panel like this: http://image.made-in-china.com/2f0j00WvCEykDrbbqY/Fiber-Optic-Patch-Panel-24-ports-FC.jpg

I plan to use the Cisco Catalyst 3560 24 IP Base Switch in unit 2, which has a blank module in which I plan to install a fibre SFP - though I don't know a lot about these! I'm assuming I'll have to find out what type of connector the providers will use at the patch panel, then order the appropriate SFP with the same connector and install it into the switch... at which point I'll be able to connect the switch into the panel using a fibre cable. If I'm going in the wrong direction here, please explain this to me .

At the other end, in unit 1, we have only layer 2 Ethernet switches that don't support pluggable modules. Is there an easy way to convert the patch panel so that it supports Ethernet? What would be the best way to do this?

I plan to split unit 2 into different networks, 192.168.X.0/24, and keep the existing network in unit 1 as 10.0.0.0/8. Our default gateway is currently 10.0.1.254. So I imagine I will have to set up the fibre interface on the layer 3 switch in unit 2 as a router interface (no switchport), and then set up the default gateway on the L3 switch as 10.0.1.254 (ip default-gateway). I realise that if any host on the 10.0.0.0/8 network wants to access the Internet, it will need its gateway setting to the address on the router's interface, and therefore traffic will be passed over the fibre link and back again to 10.0.1.254. I plan on improving this design by introducing a layer 3 switch in unit 1, but this is a long way off. I would first like to establish the network in unit 2 and get more familiar with the hardware before messing around with the already-implemented solution in unit 1.

My next question is based around how many fibre cables providers normally run between buildings. We don't need a massive amount of bandwidth - even a single cable, I imagine, would suffice. If our provider installed two cables, this would allow for redundancy, and therefore the preferred option. How many fibre interfaces would I be able to install into our L3 switch? If one of the interfaces or fibre cables failed, I'd like to be able to manually failover to the extra fibre interface, if any.

Any explanations would be appreciated, especially any alternative solutions. Thanks in advance for your help.

Harry

Leo Laohoo · ‎05-09-2013

I'm assuming I'll have to find out what type of connector the providers will use at the patch panel, then order the appropriate SFP with the same connector and install it into the switch

Connectors are easy. The most important question to ask is what kind of fibre optic cable is being rolled out? Single-Mode (long haul/long range) or multi-mode (short-range). Is the cable OM1, OM2, OM3 standard?

What is the "cut"? Straight cut (blue or white connectors) or angle cut (neon green connectors).

You can get the cables to terminate either SC or LC. Cisco SFP is LC. You can go to any reputable shop which sells fibre optic patch cables and purchase either SC-LC or LC-LC cables of various lengths.