On 11 Sep 2014 14:06, "Brandon Butterworth" <bran...@bogons.net> wrote: > > > Standard optics should be fine... > > s/should/may/
Well I'd certainly try this first with a stock inventory part before spending unnecessary money on the expensive vendor optic... > > > > I have a pair if 11 channel mux/demux's which include wavelength 1310nm. > > If that is a 20nm wide cwdm port then the sfp needs to be > on 1310 +/- 6.5nm, ie a CWDM part. A typical LR part is > free to roam between 1270 - 1360nm so chances of working are slim. Kind of. But not really free to roam... The receivers are indeed wideband but the transmitters use a laser which is a single frequency light and will not vary much. Vendors do give different tolerances for what the actual wavelength transmitted will be and this will fluctuate slightly due to the manufacturing process or temperature and indeed an optic sold as cwdm will have been checked against a tighter limit but I'd be shocked if you're buying LR that isn't almost exactly 1310. Steve > > If you have a wide 1310 port, typically called an expansion > port on cwdm mux and intended for cascading to a further > 8 channels then it will be wideband enough for LR. As you have > 11 channels I suspect you have a CWDM 1310 port and thus will > need a CWDM SFP (manufacturers often split the CWDM channels > into two banks of 8 so you can add the second set later, if they > have more than 8 they are likely using all the channels and skipping > the high water loss ones) > > > > I'm talking to now two suppliers, one in china who supplied the mux's and > > > one in Europe. > > Get a spec of the mux otherwise you're guessing. > > > > One supplier is saying I can use standard sfp optics as they use 1310 nm > > > on my 1310 port and these are cheap as chips! However the other supplier is > > > saying that these won't work as they are not as finely tuned and say I need > > > cwdm 1310 optics which are considerably more expensive! > > Both are cheap as chips if you buy from china or Flexoptix > > brandon
