LRM works on SM. I have used them a lot on cat 4500s but we mainly but not only used them for OM1 cable. Cisco link below: http://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/data_sheet_c78-455693.html
Cisco SFP-10G-LRM Module The Cisco 10GBASE-LRM Module supports link lengths of 220m on standard Fiber Distributed Data Interface (FDDI) grade multimode fiber (MMF). To make sure that specifications are met over FDDI-grade, OM1 and OM2 fibers, the transmitter should be coupled through a mode conditioning patch cord. No mode conditioning patch cord is required for applications over OM3 or OM4. For additional information on mode conditioning patch cord requirements please see: http://www.cisco.com/en/US/prod/collateral/modules/ps5455/product_bulletin_c25-530836.html. The Cisco 10GBASE-LRM Module also supports link lengths of 300m on standard single-mode fiber (SMF, G.652). Sent from a mobile device > On 15 Sep 2015, at 08:27, Nick Hilliard <[email protected]> wrote: > >> On 14/09/2015 23:15, Crist J. Clark wrote: >> I am not exactly sure of the design decisions behind the choice to use LRM >> over >> SMF to orginally connect the distro to the core when the campus was built. >> But >> given that it was working, and we already had almost enough spare LRMs on >> hand >> to complete the project, It Seemed Like a Good Idea at the Time. > > Right. :-( > >> We also have OM3 MMF between the buildings so replacing this all with SR is >> the main plan right now, but whatever the problem is with the LRM modules >> looks more like software/firmware than a problem with the fiber paths (the >> links >> always do eventually come up with good light readings and no errors), and we >> were just curious if anyone had seen this issue with 5ks and LRM before and >> found a way to deal with it. > > LRM transceivers are a bit of a curiosity tbh. I've never seen anyone > using them in production. Because they're uncommon, this has the > consequence that they will not be well debugged. In many situation this is > not a problem, but if you have dispersion problems, it can be, because > dispersion compensation on 10G SFPs is handled on the switch / router > motherboard. I.e. this can easily be a software problem. > > Also, if you're using LRM out of spec (SMF cabling instead of MMF), you > should probably expect problems. > > LR SFPs are cheap: ~$100 each for transceivers from reputable third > parties. You will save yourself time, money and heartache by sticking with > LR over SMF for longer runs and not using MMF > > Nick > > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
