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New Contributor
Posts: 3
Registered: ‎07-30-2013

DCX8510 switch is reporting RX power 109.1 uWatt or higher

Hello,

Some ports are showing as error RX power > 100uWatt

Rx power: 166.9 uWatt, Rx power: 65.3 uWatt, Rx power: 192.9 uWatt, Rx power: 141.7 uWatt,Rx power: 162.2 uWatt, Rx power: 109.1 uWatt, Rx power: 2.1 uWatt

However it's showing a port with 2.1uWatt as error.

What is the recommended value?  What could be causing this error?

Thanks in advance.

Contributor
Posts: 27
Registered: ‎10-05-2011

Re: DCX8510 switch is reporting RX power 109.1 uWatt or higher

Hi,

optical powers are usually measured in dBm.  psl see http://www.rapidtables.com/convert/power/mW_to_dBm.htm

However a typical SFP has a Window form -1dBm to -10dBm or 800uW to 100uW

if you do a sfpshow you see this information at the bottom:

                                   low        high       low         high

Temperature: 43      Centigrade    -5          85         0           75

Current:     7.338   mAmps          2.500      12.000     2.000       11.500

Voltage:     3294.6  mVolts         3000.0      3600.0    3130.0       3460.0

RX Power:    -3.3    dBm (473.1uW) 31.6   uW 1258.9 uW   31.6   uW  794.0  uW

TX Power:    -4.0    dBm (399.6 uW)126.0  uW   1258.9 uW  251.0  uW   794.0  uW

So the RX window for this 16G SX SFP is here 31.6uW to 794uW

Thus 2.1 uW is clearly out of Spec.

Check the TX power on the other site. if it is ok, you have dirty connections or a broken cable

Best

Uli

New Contributor
Posts: 3
Registered: ‎07-30-2013

Re: DCX8510 switch is reporting RX power 109.1 uWatt or higher

Thanks a lot for the information.

So this will be measure by the SFP port that is been used, correct?

So for a 8GB port the values will be different?

Contributor
Posts: 27
Registered: ‎10-05-2011

Re: DCX8510 switch is reporting RX power 109.1 uWatt or higher

This is correct.

Just do the sfpshow for the specific port you use and you will get the min/max levels for warnings and alarms.

The min/max values are usually set by the vendors (e.g Finisar, Avago, ...) but might be harmonized by Brocade.

Never checked that so far ;-)

Uli

New Contributor
Posts: 3
Registered: ‎07-30-2013

Re: DCX8510 switch is reporting RX power 109.1 uWatt or higher

Thanks a lot Uli.. Really appreciate it!

Valued Contributor
Posts: 931
Registered: ‎12-30-2009

Re: DCX8510 switch is reporting RX power 109.1 uWatt or higher

LOL and then give yourself the credit for answering your own question.

Well that;s one way to earn points.

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