CRC/alignment errors on 10G Fiber link

[lpchouinard]

Hi, 

I've been scratching my head on this one...

We've put up a new 10G link between floors (1100ft distance) and decided to use the J9150A transceiver based on this document  that state that it support 400m on OM4 fiber. One switch is a 5406  and the other one is a 3500.

When I transfert data, sometimes I get  the "00329 FFI: port B22-Excessive CRC/alignment errors. See help." message only on the 5406

FW side I was running K.15.12.0012 on both, but decided to try K.15.13.0005 on the 5406 to see if it would help, but it didn't

Here's the transceiver info for the 5406

Transceiver in B22
Interface Index : 46
Type : SFP+SR
Model : J9150A
Connector Type : LC
Wavelength : 850nm
Transfer Distance : 80m (50um), 30m (62.5um), 300m (50um OM3),
Diagnostic Support : DOM
Serial Number : CN3BG4428C

Status
Temperature : 29.347C
Voltage : 3.2784V
Tx Bias : 5.450mA
Tx Power : 0.5430mW, -2.652dBm
Rx Power : 0.0210mW, -16.777dBm

And for the 3500 

Transceiver in A1
Interface Index : 49
Type : SFP+SR
Model : J9150A
Connector Type : LC
Wavelength : 850nm
Transfer Distance : 80m (50um), 30m (62.5um), 300m (50um OM3),
Diagnostic Support : DOM
Serial Number : CN3BG44264

Status
Temperature : 29.359C
Voltage : 3.3202V
Tx Bias : 5.582mA
Tx Power : 0.5465mW, -2.624dBm
Rx Power : 0.0694mW, -11.586dBm

I've notice that the module doesn't indicate the 400m distance, was it just not added to the firmware description idk...

Should I worry or this is normal? This isn't in production yet, but I would like it to be soon

Thanks

Louis

[Chrisd131313 · Accepted solution]

Hi,

Do you have the test results from the fibre instasll? These should indicate if there are any abnormalities in the fibre/workmanship that could attribute to transmission issues @ 10Gbps.

 The only thing I can think of is that as you are running at the limit of the fibre for the bandwidth you want available the pigtails have not been spliced properly or that the grade of the fibre is not up to spec. How many cores did you run between floors? have you tried all the cores to see if you get any improved results? Also do you have spare SFP+s to test with? Can you confirm the CRC/Alignment erros go away if you connect the two switches together with a fibre patch lead of a couple of metres?

Apart from this, the only other suggestion I have is to put in Single Mode instead of Multimode - I know this is no real help!! but if you are getting close to physical limits its always worth paying a little bit more fo the SFP+ because fibre these days is pretty much the same cost regardles of the type you go for.

[Richard Brodie_1]

I have no idea what the nominal levels are but you are down quite a lot on RX power at the 5406 end compared to the other.  I would try reseating, trying new patch cables  and/or crossing the pairs over, see if you can get the level up a bit.

[lpchouinard]

Thanks for the suggestions, we have have 3 pairs between floors.

We tried another one and now the RX power is much better and there's not any error anymore.

Transceiver in A1
Interface Index : 49
Type : SFP+SR
Model : J9150A
Connector Type : LC
Wavelength : 850nm
Transfer Distance : 80m (50um), 30m (62.5um), 300m (50um OM3),
Diagnostic Support : DOM
Serial Number : CN3BG44264

Status
Temperature : 29.656C
Voltage : 3.3204V
Tx Bias : 5.690mA
Tx Power : 0.5456mW, -2.631dBm
Rx Power : 0.4797mW, -3.190dBm

Transceiver in D22
Interface Index : 94
Type : SFP+SR
Model : J9150A
Connector Type : LC
Wavelength : 850nm
Transfer Distance : 80m (50um), 30m (62.5um), 300m (50um OM3),
Diagnostic Support : DOM
Serial Number : CN3BG4428C

Status
Temperature : 28.875C
Voltage : 3.2824V
Tx Bias : 5.494mA
Tx Power : 0.5415mW, -2.664dBm
Rx Power : 0.3467mW, -4.601dBm

Thanks for the help guys