Most SFP/XFP have upc connectors until you get above 5(ish) db of power, then you'll start to see APC and/or E2000 connections. You'll end up using a hybrid jumper (APC one end, UPS on the other). If you're looking for quality jumpers look at Clearfield or Corning. ADC makes tracelite jumpers that illuminate if that's part of your need. You should only see a .1-.2 db increase in loss for an APC connecter vs a UPC connector. -----Original Message----- From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Lorell Hathcock Sent: Tuesday, February 23, 2016 7:12 AM To: nanog@nanog.org Subject: APC vs UPC? NANOGians: APC wins! My real question is surrounding the connection on the SFPs themselves. In general terms are the LC connectors on SFPs considered UPC or APC? If the answer is UPC and if I am inheriting and/or building a network of single mode fiber with APC SC connectors, then is the best practice to use LC UPC to SC APC fiber jumpers? If so, can anyone point me to a source for said jumpers that is (1) quick and (2) good? Any thoughts on the same idea of mismatched fiber jumpers connector types to use on OLMs and OLSs? OTDRs? The concern here is to use the best possible fiber connector types (e.g. APC or UPC) when connecting lasers to my OSP fiber which uses APC with consideration to the optimal connector type for the laser transceiver. My thoughts are to use fiber jumpers with UPC connectors on the laser side with APC on and throughout the OSP, but if it should be purely APC everywhere, then that is what I need to know. Thanks! Lorell Hathcock