Fibre Advice

[DRGL]

I could do with a little fibre advice!! I've got two seperate networks to link together,both are running on CAT5e @ 10/100. There are 20 machines on one network and abround 50 on the other,the buildings are 180M apart but ducting is already in place.They will both share one server. Should we link these network together using Gigabit or is 100BASEFX fast enough? With 100BASEFX is the bandwidth shared or would each machine still have 10/100 access to the servers?? Thanks for any help/advise/experience guy's!!

 

[jimbopalmer]

50 nanometer multimode fiber would support both 100 and gig fiber speeds, so would 62.5 nanometer but it would be closer to it's limits at gig speeds (220 meters)

The speed of the fiber will only limit the traffic BETWEEN the buildings, not the traffic within the buildings.

Remember that unless multiple machines in Bulding A are talking to multiple machines in Bulding B, no conversation can be faster than your NIC speed.

I tried to remain child-like, all I acheived was childish.

 

[DRGL]

Thanks for the info,multiple machines at one site will communicate with the server at the other site,does this require gigabit or would 100BASEFX be OK?? What i require is the machines at one site to see no differnce in speed when accessing the server(via fibre) when compared to the machines accessing the server at the other site(all on 10/100 CAT5e) Thanks.....

 

[jimbopalmer]

Unless the server itself uses a NIC that is set to gig, its total bandwidth to all clients is 100 meg, so there cannot be a bottleneck to it with 100 meg fiber.

Increasing the number of clients may slow them all down, but the ones in the new bulding should not be noticabley slower than those in the old building.

I tried to remain child-like, all I acheived was childish.

 

[DRGL]

Thanks for that,i guess if we want to future proof it we should install a 1 Gigabit link AND Gigabit link from the servers to a Gigabit switch? I think the main issue was would the remote building see a speed difference using the fibre link which you have answered-thanks very much!!

 

[jimbopalmer]

Yes, this is a good time to spend money on gear you grow into rather than gear you grow out of, I am not trying to discourage that!

I tried to remain child-like, all I acheived was childish.

 

[DRGL]

final question,62.5/125 or 50/125?! I undersatnd 50/125 gives better bandwidth but always thought 62.5/125 was the newer fibre??Any implications/advantages on using either?(like are most switches compatible with one or both?) Thanks again.....

 

[jimbopalmer]

I had always used 62.5 until we got gig gear, it can go 220 meter with 62.5 and 550 meters with 50

http://www.graybar.com/vip/vipwhitepaper/FiberSolutions.html

I tried to remain child-like, all I acheived was childish.

 

[DRGL]

So is distance the only issue? It's only got to cover 180M max,sorry for the Q's!!......

 

[DRGL]

and out of interest,what would happen if you used 50/125 patch leads on a 62.5/125 fibre link and vice versa?

 

[Jtodd]

No problems when the light is traveling from the 50 into the 62.5. I think it's about a 7db loss of light when traveling from 62.5 into 50.

Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay

 

[DRGL]

Thanks for that!