[c-nsp] Cisco SFP

[Anderson Levi]

Thanks.

On Thu, Jun 18, 2009 at 10:49 AM, Buhrmaster, Gary <gtb at slac.stanford.edu>wrote:

> > What are the implications of using a GLC-ZX-SM module to light a
> > stretch of 20 - 30km? Would I need to add an attenuator, given that 20km
> is well
> > below the 70km limit?
>
>
> As always, the answer is "it depends", because
> it is the optical power, not distance, but usually
> if the link is <~25km you can expect to need an
> attenuator.  The typical transmit is ~ 0-5dBm,
> and the max receive power is ~ -3dBm.  If you
> overload the receiver, you could damage the
> device, or shorten is life, or cause various
> physical link errors to be reported as the
> optics is overloaded.  So, in all cases,
> measure the received power, and add in the
> needed attenuation.
>
> Reference:
>
> http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6577/product_data_sheet0900aecd8033f885.html
>
> Gary
>