GLC-BX-D(U) SFP

[dmitry.bogdanov]

Hello. I'm choosing SFP for cisco 3750-X. In datasheet for GLC-BX-U(D) min transmit power is -9 dBm, min receive power is -19.5 dB. So max insertion loss in channal is about 10.5 dB. But in this datasheet it's just 5.5 dB for GLC-BX-D and 6 dB for GLC-BX-U. In that case, what max loss is right?

[Tom Randstrom]

The data sheet indicates "standard SMF with an operating transmission range up to 10 km."  These transceivers integrate a WDM filter (~ 1dB additional loss per end) to add and remove the 1310nm and 1490nm signals on the single fiber. 

Operating outside the Cisco recommended range will be an unsupported deployment.

Hope this helps!

[viyuan700]

I think they are just saying it can have any  value between the range  for Transmit/Receive but Max Insertion loss they are going to suspport is 5.5/6dBm.

Cisco is going to provide Max Insetion loss of  5.5 /6 dBm for those cards. So if the transmit power is -8dBm you can expect receiver sensitivity to be -13.5 to -14 dBm. For any problem cisco is going to support for 5.5 /6 dBm of loss.

It is possible that you can get more Max Insertion Loss (means distance) but don't expect Cisco to support it. With -9 dBm as Min Tranmit it is impossible to get the -19.5 dBm the Min Receive Sensititvity so possible they are thinking to extend some spec for more distance in future.

[dmitry.bogdanov]

Thanks.