Re: Low to Mid Range DWDM Platforms

[Chad Lamb via NANOG <nanog () nanog org>]

XKL is still here ...
Some caveats on 400G ZR/ZR+ devices:
- They are power hungry, cooling is a challenge.  800G even more so.  
The OSFP package for 800G looks like the better choice than QSFP-DD for 
this reason.  We'll see, we need more mileage on this.
- For the ZR devices, not all vendors are equal.  Some support 4x100GE 
as well as 400GE, if that matters to you.  Some have integrated BERT and 
encryption, some do not.
- Do not plan on inter-operating different vendors of ZR+ devices. They 
will interoperate only in ZR mode.
- Plenty of filter options out there if you are putting the ZR/ZR+ in 
your router.  I'll throw a plug in for the Coherent free space DWDM 
filter. Free space technology has the best IL and isolation numbers.  
Coherent hasn't packaged it in a module for easy racking yet (XKL can 
provide that).  So if you aren't adding an EDFA, the lowest IL you can 
get helps your reach.
- If you have at least a few 400G channels, add an EDFA and use the Tx = 
-10dBm devices, rather than the Tx = 0dBm devices.  This is cost 
effective.  The EDFA also extends the reach considerably.  You can 
launch each channel up to +10dBm or more, for a modest number of 
channels, without getting in trouble with fiber non-linearities 
(four-wave mixing).

Chad


On 10/7/23 10:35 PM, Mark Tinka wrote:
> Finally, the name came to me :-):
>
> https://www.xkl.com/
>
> Looks like they are still in business.
>
> Mark.
>
> On 10/6/23 16:02, Mark Tinka wrote:
> > On 10/6/23 15:52, Dave Bell wrote:
> > > Smartoptics?
> > >
> > > https://smartoptics.com/
> >
> > Not them.
> >
> > I want to say they had an "X" in their name, but memory is fuzzy.
> >
> > Mark.