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</o:shapelayout></xml><![endif]--></head><body lang=EN-AU link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Since you are running a single mode SFP on Multimode fibre a first question is whether you are using mode conditioning cables at the end points?<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>I’ve included a vendor link here, please don’t shoot me </span><span style='font-family:Wingdings;color:#1F497D'>J</span><span style='color:#1F497D'> but it specifically discusses the issue<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><a href="http://www.cisco.com/en/US/prod/collateral/modules/ps5455/product_bulletin_c25-530836.html">http://www.cisco.com/en/US/prod/collateral/modules/ps5455/product_bulletin_c25-530836.html</a> <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Since a LH/LX has a decent amount of dB power budget available before errors creep in I’d assume this combined with a large number of reflective surfaces (6 pairs of patch panels with patch leads is 20 – 40 reflective surfaces alone) and the vaguaries of badly looped fibre patches could mean total end to end loss is huge<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>I don’t suppose you have access to a basic optical power meter?<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Darren<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> ausnog-bounces@lists.ausnog.net [mailto:ausnog-bounces@lists.ausnog.net] <b>On Behalf Of </b>Qui Le<br><b>Sent:</b> Friday, 20 April 2012 10:45 AM<br><b>To:</b> ausnog@lists.ausnog.net<br><b>Subject:</b> [AusNOG] Fiber connectivity<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We run 550m of OM1 fibre from our Cisco core to a remote site over 6 hops included rack to rack and we can not<o:p></o:p></p><p class=MsoNormal>seem to get any connectivity. Using both Cisco GLC-LH-SM transceivers at both the Core & access Switch.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Does anyone know if there are hops limitations for long haul fibres.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Any advise is much appreciated.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-family:"Arial","sans-serif";color:#7E7E7E'>Qui Le</span></b><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><br>Please consider the environment before printing this email.<br>=====This message is intended for the addressee(s) named and may contain confidential information.<br>If you are not the intended recipient, please delete it and notify the sender.<br>Views expressed in this email are those of the individual sender and are not necessarily the views of the Sydney Opera House Trust=====<o:p></o:p></span></p></div></body></html>