Hi

thanks for the reply

as we noticed that there is some difference in the TX and RX level between the 1G and 10G modules

Interface Tx Max Tx Min Rx Max Rx Min

1000Base Lx -3 -9.5 -3 -19

10 Gig LR 0.5 -8.2 0.5 -14.4

its an single mode dark fiber between point to point distance around 8km max

Hi Giuseppe,

In multimode fiber it is possible that cable is suitable for 1G but not 10G but if it is Single mode then its capacity is much more than 10G.

Hi Vinod,

R u trying to connect 1G to 10G. Power levels are different for different card.

You cannot connect a 1G Optical card to 10G Optical card like you connect a RJ 45 1G to 100Mb.

If you are connecting two 10G cards then see check if you have anything which is increasing the Optical loss, it can be some dirt on patch cable etc.

10Gig LR can go till 10Km so 8Km is unless there is more optical loss then it should be.

You mentioned that you are getting loop through a mux which MUX it is do you have idea?

"In multimode fiber it is possible that cable is suitable for 1G but not 10G but if it is Single mode then its capacity is much more than 10G."

MMF is still possible for 10G but in a very short distance. Not with the LR optic though.

http://www.cisco.com/en/US/prod/collateral/modules/ps2797/ps5138/product_data_sheet09186a008007cd00_ps5251_Products_Data_Sheet.html

My only suggestion on this is check out the signal strength (dBm) of at the remote end.

HTH,

jerry

Thanks Jerry,

Made a mistake in forming the sentence so it looks like 10G not possible with MMF.

Cable distances in fiber are limited by

Power

Dispersion

PMD (Polarization Mode Dispersion)

MMF are limited by Dispersion as the pulse is broadned so much after short distance (too much BER) that there is no need for Long Optics for MMF.

Below 40G, SMF mostly are limited by power of Optics.

At 40G, even though SMF it is not limited by Power or Dispersion it is limited by PMD. As PMD effect is so effective at that rate.

Hello Vinoth,

as Vishwa has noted you should be fine but you can only connect 10 GE to another 10 GE port.

1GE and 10GE are not compatible it is not a question of power levels they are too much different.

Hope to help

Giuseppe