Effects of using single mode fibre with media converters intended for multi mode.

[robmurphy]

Has anyone come across the above situation, i.e. a fibre link under 300M using single mode fibre, but terminated on media converters or SFPs for multi mode fibre.

I'm not suggesting fitting this. I would just like to know what effects the above is likely to have. I have seen this at a customer site. The fibre run is less than 300M, but its been done with single mode fibre. The media converters are an old no name brand, and its not clear if they are for single or multi mode fibre.

After checking I noticed some SFPs for the Cisco SMB switches are show as compatible with both single and multi mode fibre. Is there likely to be any problem using them with a fibre run of 200 to 300 metres, or would they need an attenuator as for single mode fibre its a very short run.

Thanks in advance.

Rob.

 

[imagoon]

What size is the fiber? Like any "out of spec" install it might work, work poorly, or simply not work.

Fiber comes in a couple of sizes as would the connectors on the convertors, obviously miss matched sizes will degrade the line.

I have used 62.5 single mode as a temp patch in a 62.5 multimode before without issue though.

edit: Mismatched fiber sizes also can break / chip the fiber or receiver. If you force a 62.5 mil fiber in to a 50mil receiver, it will likely break something and scratch other stuff.