Re: [uknof] CWDM Advice needed
Standard optics should be fine... s/should/may/ 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. 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
Re: [uknof] CWDM Advice needed
It depends on the separation of 1310 channel from the other colours, we use 1+8 Mux's (1310 with the 'standard' 1470-1610 8 ports), and standard LX is fine in the 1310 ports. However if you have colours close to 1310 (1330 or 1350 for example), then a normal LX will stamp all over the surrounding colours. The same applies if you try and use a 1550 ZX or ER optic in a 1550 CWDM port. I hope that helps... Regards... Ben Sent from my iPhone On 11 Sep 2014, at 01:49, Joseph Waite joeli...@hannontelecom.net wrote: Looking for some advice here. Deploying cwdm onto a dark fibre link in next few weeks. I have a pair if 11 channel mux/demux's which include wavelength 1310nm. I'm talking to now two suppliers, one in china who supplied the mux's and one in Europe. 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! Can anyone here advice which is correct? Regards Joe Waite
Re: [uknof] CWDM Advice needed
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
Re: [uknof] CWDM Advice needed
Also beware of the fringes - something that works on your span today might not after a fibre break or other incident. Cheers Neil Sent from my iPhone On 11 Sep 2014, at 10:08, Brandon Butterworth bran...@bogons.net wrote: Well I'd certainly try this first with a stock inventory part before spending unnecessary money on the expensive vendor optic... I'd find the mux spec before puting something live that may only be on the edge of staying live Vendors do give different tolerances for what the actual wavelength transmitted will be and this will fluctuate slightly due to the manufacturing process Yes, that's the wide range I quoted, devices can be anywhere within that (I've measured them), there's no reason for non cwdm be close to 1310 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. It may be some manufacturers use the same lasers for both parts but usually the cwdm have a laser designed for stability, which costs more (DFB vs Fabry-Perot) brandon
Re: [uknof] CWDM Advice needed
Ok cheers guys! Think that has answered my question! I'll stick to the cwdm optics! Would rather pay a little more and not have issues! Regards Joe Waite On 11 Sep 2014, at 12:10, Neil J. McRae n...@domino.org wrote: Also beware of the fringes - something that works on your span today might not after a fibre break or other incident. Cheers Neil Sent from my iPhone On 11 Sep 2014, at 10:08, Brandon Butterworth bran...@bogons.net wrote: Well I'd certainly try this first with a stock inventory part before spending unnecessary money on the expensive vendor optic... I'd find the mux spec before puting something live that may only be on the edge of staying live Vendors do give different tolerances for what the actual wavelength transmitted will be and this will fluctuate slightly due to the manufacturing process Yes, that's the wide range I quoted, devices can be anywhere within that (I've measured them), there's no reason for non cwdm be close to 1310 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. It may be some manufacturers use the same lasers for both parts but usually the cwdm have a laser designed for stability, which costs more (DFB vs Fabry-Perot) brandon
[uknof] CWDM Advice needed
Looking for some advice here. Deploying cwdm onto a dark fibre link in next few weeks. I have a pair if 11 channel mux/demux's which include wavelength 1310nm. I'm talking to now two suppliers, one in china who supplied the mux's and one in Europe. 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! Can anyone here advice which is correct? Regards Joe Waite
Re: [uknof] CWDM Advice needed
Standard optics should be fine... On 11 September 2014 08:48, Joseph Waite joeli...@hannontelecom.net wrote: Looking for some advice here. Deploying cwdm onto a dark fibre link in next few weeks. I have a pair if 11 channel mux/demux's which include wavelength 1310nm. I'm talking to now two suppliers, one in china who supplied the mux's and one in Europe. 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! Can anyone here advice which is correct? Regards Joe Waite
