fiber cable

[bluesea2010]

Hi,

If I am laying cable in a campus building, which  fiber  mode ( single mode or multimode ) needs to be selected 

Thanks 

[Leo Laohoo]

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@bluesea2010 wrote:

SFP-10/25G-CSR-S will work 300 meter (om4)  depends upon fiber quality .what  quality exactly 

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10 Gbps is doable at 300 metres.  This is not my concern. 

My concern is 40- and 100 Gbps.  

If the plans are 100 Gbps in the next 5 years, then get two x 12 core OS2 (diverse path) and make sure to "light up" each strand even if they are not being used.  

[balaji.bandi]

SFP-10/25G-CSR-S will work 300 meter (om4)  depends upon fiber quality .what  quality exactly 

if your network not go beyond 10G forever or lifetime, you are good to go, but as I mentioned network requirements year on year going like crazy, so if you looking to protect your investment go with single-mode fibre

[Reza Sharifi]

Hi,

I could see the fiber optic 10g  single-mode price decreased a lot. In that case  for future  growth laying a single  mode is  better  than 

multi -mode ?

It is really up to you. As I said before if you have the budget to install SM fiber and the cost of the SM SFPs is not an issue, go for SM, but if your distance is within 300 meters, SM is not really necessary, as MM (OM4) can do the job with no issues.

As I said, the only time you are forced to use SM is when providers hand off circuits to you, and that is because that is usually the only thing they have.

The other issue that you need to consider is that if this is for a campus environment, you may run into a situation when you need to go from one router to another or one a router to switch, etc.. within the same room and so, SM is not really suitable for short distances as it was originally designed for longer distances. 

HTH

[bluesea2010]

Hi @Reza Sharifi 

SM is not really suitable for short distances as it was originally designed for longer distances 

Does it mean is there any issue  if  it is short distance and the fiber is sm  ? 

Thanks