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

Thank You Bob Evans CTO

Hello,

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 ?

Is it true that if the rx power is higher than (x?) then it shortens the life of the optics ?

Yes, but thats only true about single mode frequencies not multimode (MM) because those are not as powerful. All MM is expected to go a very limited distance, so levels are never high. We have MM 3 foot jumpers between gear running for years.

(assumption being made here is that MAX Rx Power is not being exceed as per the spec sheets of the optics)

Regards

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

Faisal, You don't need to worry about power range when connecting SR or LR. However, an ER or ZR on a loopback can damage Rx. The strength of the receiving signal is always under the tolerance allowed. The 850nm Light is attenuated very quickly because of the MMF and the 850nm light source. This light source is more like an LED than a Laser. The MTTF on any transceiver is 50,000 hours at room temperature. A bigger factor is high temperature, because the chip is a semiconductor. Eric Litvin President eric@lumaoptics.net Direct: (650)440-4382 Mobile:(*650)996-7270* Fax: (650) 618-1870 On Wed, Feb 11, 2015 at 12:48 PM, Faisal Imtiaz <faisal@snappytelecom.net> wrote:

Hello,

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 ?

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)

Regards

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

-- Eric Litvin President eric@lumaoptics.net Direct: (650)440-4382 Mobile:(*650)996-7270 <650%29996-7270>* Fax: (650) 618-1870