HPE EVA Storage

Fibre Cabling Suggestions

 
Steven Clementi
Honored Contributor

Fibre Cabling Suggestions

Let me describe the situation:

I have 2 Cisco MDS9124's that I am trying to connect 2 sites with.

Here is the situation:

The fibre between the buildings is said to me "multimode". It is also said to be a straight through patch, no mechanical/digital equipment in between. The distance is about 3000 feet.

The customer already has several other devices connected site to site using these fibre pairs, simply using 62.5/125 multimode patch cables. These are NOT SAN devices though.

When I connect up the MDS's, I do not get any connectivity. Is it simply too far out of range for multimode cables and a SAN environment?

I have long wave sfp's in the switches and they work fine if I directly attach a simple lc-lc patch cable between them. (I have more switches onsite that I tested with).


What would you suggest for a situation like this? Would using single mode cables help in connecting the sites?

Steven
Steven Clementi
HP Master ASE, Storage, Servers, and Clustering
MCSE (NT 4.0, W2K, W2K3)
VCP (ESX2, Vi3, vSphere4, vSphere5, vSphere 6.x)
RHCE
NPP3 (Nutanix Platform Professional)
4 REPLIES 4
Uwe Zessin
Honored Contributor

Re: Fibre Cabling Suggestions

3000 feet is, what? more than 900 meters?

A 62.5 micron multimode cable of OM1 quality /(200 MHz/kilometer) is good for 200 meters when using 1 GigaBit/second. I doubt that you will get a working link, even if you use multi-mode SFPs.

Long-wave GBICs/SFPs require a 9 micron (single-mode) cable. They work on multimode cables when the distance is short, but not on _that_ distance.

The customer _does_ need single-mode cables or some kind of IP bridge with a lower bandwidth.
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IBaltay
Honored Contributor

Re: Fibre Cabling Suggestions

Hi,
maybe some useful info could be find in the SAN design guide:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00403562/c00403562.pdf?jumpid=reg_R1002_USEN
the pain is one part of the reality
Uwe Zessin
Honored Contributor

Re: Fibre Cabling Suggestions

maybe? No really ;-)

The SAN Design Guide contains a lot of useful information in one place if you are dealing with different core diameters, mono/multimode, different speeds and so on.
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Steven Clementi
Honored Contributor

Re: Fibre Cabling Suggestions

Thanks. We ended up going with Multimode Extenders between sites. If you need more information about models we used, just ask.

Steven
Steven Clementi
HP Master ASE, Storage, Servers, and Clustering
MCSE (NT 4.0, W2K, W2K3)
VCP (ESX2, Vi3, vSphere4, vSphere5, vSphere 6.x)
RHCE
NPP3 (Nutanix Platform Professional)