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New Member

Advice Please...!!!

We have 2 buildings currently interconnected with Multi-mode Fibre over a distance of 1.2Km, we currently have Ethernet running across this link at 100Mb/s, is it possible to increase the speed of this link to 1Gb.....??? All the documentation I have read appears to indicate that the multimode fibre is incapable of supporting 1Gb or does anyone know differently....????

Thanks for any responses.......

New Member

Re: Advice Please...!!!

Hi Sean,

Here's a good link regarding standards:

It would appear at a glance that the Gigabit EtherNet standard IS supported over MM



Re: Advice Please...!!!

The SX GBIC will not make the distance you require, the MAX you will get 550m, this URL will give you all the distance capabilities for the Cisco GBIC.

New Member

Re: Advice Please...!!!

Thanks for replying......!!!

OK it looks like Multi-mode is limited to 550 metres at 1GB Ethernet......

Single mode will run at up to 10Km depending on the equipment/supplier.....

Re: Advice Please...!!!

Thats about the sum of it. :))

The other way to do it was if you had multiple Fibre Runs between sites then create and Etherchannel..


New Member

Re: Advice Please...!!!

I am not sure of the distances, but you could try a special fiber jumper and Lx cards. We were told that we "Might" need this for our connection between two buildings over MMF. We are using LX Gbics. After testing, we found that it worked either way, so we left the special jumpers in. The jumper is called any number of things. I might combine the names, but it was along the lines of a mode conditioning offset launch cable. It makes the multi-mode cable act more like single mode. I'm sorry I don't have more info, but this might point you in the right direction.

New Member

Re: Advice Please...!!!

Multimode will definatly run Gig but the distance is the key to this not the

fibre. - I would assume the fibre is 62,5/125 Multimode ?

Here is the cisco bit:')">

Pretty conclusive !! Surprised that a Multimode fibre is installed over 1.2km as

most would have installed single mode!

at least you have an answer

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