Connecting two different Cisco Switches using Fibre

Question

I have two Cisco Catalyst 2960-24TC-L switches and would like to connect them using fibre over a distance of 200Meters. According to cisco, the switches has two SFP ports, which I can clearly see on them but my issue is I do not know where or how to proceed knowing that I am not into networking at all. All I want to do is to make sure I am on the same page with the network engineer I will be contracting so they wont be here telling me what they want and not what we need.

Any help will be highly appreciated.

Answer 1

You can use short range SFP optics for this. The Cisco part number is GLC-SX-MM, and the cost is about $75-$100 each (you'll need two). The person installing your fiber should use 50uM multimode fiber (62.5uM is also useable, but you're getting close to the maximum range) with LC type connectors.

Answer 2

You can check Cisco SFP Modules for Gigabit Ethernet Applications Data Sheet

There you can see that 1000Base-SX SFP (part-number GLC-SX-MM) using 62.5 um MMF reaches 220 or 270 meters (depending on modal bandwidth of the fiber). However, if switches are 200 meters apart it could be easy that cable runs are actually longer than 220 meters.

Of course, you can make sure you won't exceed distance limit by using 50 um OM2 MMF , which covers up to 550 m with 1000Base-SX SFP.

Answer 3

Multimode fiber has a bigger core and uses less precise optics than singlemode fiber. This makes the transceivers (SFPs in your case) cheaper than their singlemode counterparts. This also means they can't shoot over as long of a distance as singlemode can because the light gets scattered within the fiber and has poor long-range characteristics.

OM3 is a manufacturing specification for multimode fiber. This should probably work well for your needs. Wikipedia has a good comparison of different multimode fiber specifications: http://en.wikipedia.org/wiki/Multi-mode_optical_fiber

You'll need compatible (matching) SFPs on both ends of the fiber and they'll need to match the type of fiber (singlemode vs multimode). Since the limiting factor for speed in this case would be the SFPs, you'd be fine to get OM3 cable installed and regular gigabit SFPs. When you're ready to upgrade to a 10Gbps connection, you would need to upgrade your SFPs and possibly your switches.

You'll also need to take into consideration what sort of environment your fiber will be in. If it's run inside a building, you'll be fine with regular fiber, but if it's run through the ground or in an area where it's susceptible to damage, you'd be better off with OSP (OutSide the Premises) fiber cable with sheathing.

Answer 4

If this is a new installation I'd go ahead with OM-3 Horizontal cabling. Works fine with LED transceivers (1GB as long as you use 50/125 patch cables) and will work 10G-40G if you upgrade in the future.

Answer 5

The type of SFP transciver you use is determiend by the fiber type.

You have to chose between singlemode and multimode. Singlemode fiber is cheaper than multimode but the transcievers are more expensive and the termination must be performed more carefully.

Singlemode fiber tends to be more future proof than multimode. Current high grade multimode fiber (OM4) will support 1G and 10G over the distance you are working at but is likey to have difficulty handling anything above that.

I would suggest asking your installation contractor to price out both OM4 multimode and singlemode options and if the cost of the singlemode option is the same or only a little higher to go with the single mode option.