[c-nsp] Are these DWDM optics compatible?

[Andrew Gallo]

On 10/27/2010 4:38 PM, Michael K. Smith - Adhost wrote:
> Here is the ITU 100 GHZ grid.
>
> http://www.telecomengineering.com/downloads/DWDM%20ITU%20Table%20-%20100
> %20GHz.pdf
>
> ITU 52 is 35.82.   Whether or not it will work at .92 is moot, IMO.  I
> would tell your vendor to give you optics that follow the ITU grid.  .92
> doesn't show up anywhere in the ITU grid, even at 50 Ghz.  The spectral
> width on the optics is .2nm, but I wouldn't want to be sitting on the
> edge of the acceptable limit.
>
> Mike
>
> --
> Michael K. Smith - CISSP, GSEC, GISP
> Chief Technical Officer - Adhost Internet LLC mksmith at adhost.com
> w: +1 (206) 404-9500 f: +1 (206) 404-9050
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>
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
>> bounces at puck.nether.net] On Behalf Of Steven Raymond
>> Sent: Wednesday, October 27, 2010 11:20 AM
>> To: Cisco Network Service Providers
>> Subject: [c-nsp] Are these DWDM optics compatible?
>>
>> Ordered part number DWDM-X2-35.82 , and received part labeled DWDM-
>> X2-35.92 (non-Cisco branded X2 optics).  Vendor says oh they are close
>> enough to work, there's a .2nm working range for ITU channel 52
> signaling.
>> In fact they claim that DWDM-X2-35.82 is the very same part, just with
> a
>> different (or in this case typoed) label on it.  Does anyone have
> experience to
>> confirm or reject the vendor's claim?
>>
>> Looking here:
>> http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6576/data
>> _sheet_c78_489725.html
>> I can almost buy their argument, and google perhaps confirms by
> returning
>> "No results found for "DWDM-X2-35.92"."  Makes me wonder if all these
>> parts are simply the same hardware, and upon ordering they simply tune
> the
>> frequency into an eprom for whatever was ordered, apply a label and
> ship it
>> out?
>>
>> Thanks!
>>
>>
>>
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The tolerances are tight, sure enough, but should work.  We've seen
Cisco branded optics start drifting outside of the channel plan.  If
this starts happening, the filters will clip the signal and the receiver
will start complaining about low power.