<div dir="ltr"><div><div>Hi Brian,<br><br></div>Thanks a lot for your thoughtful and informative analysis. We're using 1000BaseLX SFP, I push our team to go with your first recommendation making it uniform with SM (or MM) along the full path.<br><br></div>BR,<br>Awal<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Feb 24, 2016 at 9:23 PM, Brian Candler <span dir="ltr"><<a href="mailto:b.candler@pobox.com" target="_blank">b.candler@pobox.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div>On 24/02/2016 14:18, Md. Abdul Awal
wrote:<br>
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<blockquote type="cite">
<div>We have a probable link to provision with a SM-MM-SM fiber
combination shown below:<br>
<br>
<img height="107" width="498"><br>
<br>
</div>
Wondering if there is any issue in terms of QoS, data flow or any
other service related problem in the long run. I'd appreciate your
comments on that.<br>
</blockquote></span>
I would strongly recommend you don't do this: the amount of light
which can get from the MM into the much narrower SM is very low, and
the majority will be reflected back.<br>
<br>
What interfaces are you using at each end? A 1000baseLX SFP is
capable of running over either MM or SM, so if you simply use SM
patch cords at both ends then it's SM end-to-end, and all the
problems go away.<br>
<br>
If you are using 100baseFX media convertors then it might work, but
media convertors are unmanaged and notoriously unreliable. Putting
an SFP in a managed switch will be a much more robust solution.<br>
<br>
Something like the Netgear GS110TP costs about $150 and gives you
two SFP ports, 8 gigabit copper ports (with PoE!), and is fully
manageable (SNMP, HTTP, and telnet on port 60000)<br>
<br>
Regards,<br>
<br>
Brian.<br>
<br>
P.S. There are special "mode conditioning patch cords" you can get,
but these are used for the opposite situation - i.e. where the long
link is multi-mode and the tails are single-mode. (The idea is to
get slightly longer reach from existing MM plant)<br>
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</blockquote></div><br></div>