And a follow-up to my original question...

I'm reading the Cisco SFP GBIC-SH spec for 50u OM3 and it shows a rating of 1000m? Really? That's better than the LH rating over the same fiber (550m)? Hi Jeff, I don't know of any optics with a 1km reach over MMF at either 1G or 10G rates. Over OM3 fiber you can get ~260-300 meters of 10G, over older MMF you can potentially get much less, it depends on the exact signal you're

re: "The grief caused over the long run by having more installed MMF plant, especially as you try to move to 10G speeds and beyond, is IMHO not worth the relatively small short term cost optimization." A good point, which becomes particularly germane moving forward. According to a TIA presentation I attended today, a 40G link will require eight (8) strands of 8MMF. And the way things look now, a 100Gbps link will require twenty (20) strands of MMF. Neither is likely to reach beyond 100 to 150 meters max. A single pair of SMF will suffice for both and cover eminently greater distances. Until now the tradeoffs have been a no-brainer, favoring MMF. But as the number of strands begin to add bulk and handling issues and the price points continue to fall for SMF at 10G and above, it will become more trying to decide. Incidentally, there's a couple of good pieces in the March 2010 issue of Lightwave Mag on the subject of falling prices of Photonic Integrated Circuits (PICs) at 10G and above, and one on advancements being made in Planar chips as well on pp 6 and 24, respectively,' here: [1]http://online.qmags.com/LW0310/Default.aspx?sessionID=43F4572DBED1C1 526DB2E9CBB&cid=218039&eid=14800#pg1 Frank --- ras@e-gerbil.net wrote: From: Richard A Steenbergen <ras@e-gerbil.net> To: Jeff Kell <Jeff-Kell@utc.edu> Cc: nanog@nanog.org Subject: Re: RE: Inside plant 10G fiber specs? Date: Tue, 16 Mar 2010 00:39:39 -0500 On Mon, Mar 15, 2010 at 10:15:51PM -0400, Jeff Kell wrote: trying to pass. Yes you can get 550 meters with 1G LX over MMF, but the MMF itself is ultimately what is limiting you. I recently did a NANOG presentation on some of this, you may want to take a look at: http://www.nanog.org/meetings/nanog48/presentations/Sunday/RAS_opticaln et_N48.pdf Personally my take on this particular problem is to stop doing MMF runs and standardize on SMF where possible. If you do any amount of shopping at all you can find optics for SMF which are barely any more expensive than optics for MMF, especially if you're only talking about 1GE or 10G SFP+. The grief caused over the long run by having more installed MMF plant, especially as you try to move to 10G speeds and beyond, is IMHO not worth the relatively small short term cost optimization. -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC) References 1. http://online.qmags.com/LW0310/Default.aspx?sessionID=43F4572DBED1C1526DB2E9CBB&cid=218039&eid=14800#pg1