Re: MultiMode Fiber Connectivity... (850nm) Power Question

[Faisal Imtiaz <faisal () snappytelecom net>]

Thanks Justin...

Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232

Help-desk: (305)663-5518 Option 2 or Email: Support () Snappytelecom net 

----- Original Message -----
> From: "Justin M. Streiner" <streiner () cluebyfour org>
> To: "NANOG" <nanog () nanog org>
> Sent: Wednesday, February 11, 2015 12:41:23 PM
> Subject: Re: MultiMode Fiber Connectivity... (850nm) Power Question
>
> On Wed, 11 Feb 2015, Faisal Imtiaz wrote:
>
> > I was looking for feedback on the following question:-
> >
> > When connecting two MM SFP/SFP+/XFP 's together...(short range).
> >
> > What should be the best practice receive power range ?
>
> SX (1G) / SR (10G) / SR10 (100G) gear generally has a receive threshold
> that's higher than the maximum launch power.  They are designed for
> short-reach applications (in-building, data center, etc), so no
> attenuation is needed.
>
> > Is it true that if the rx power is higher than (x?) then it shortens
> > the life of the optics ?
> > (assumption being made here is that MAX Rx Power is not being exceed as
> > per the spec sheets of the optics)
>
> On short-reach optics, this should never be a problem.  On long-reach
> optics, receiver saturation will generally result in link errors/flaps,
> and possibly high rx power warnings (depending on the gear on the
> receiving end), however, these can be addressed using in-line attenuators.
>
> On very long-reach optics, such as ZX (1G) and ER/ZR (10G), it is possible
> to damage the receivers with too hot of a signal because they are designed
> for long spans and a certain amount of distance-based attenuation is
> factored into the optical power budget.
>
> jms