Apologies for the previous poorly-formatted post - hopefully this one is more
readable :-P
We need to run 10GbE dark fiber between two 3750-X switches (each with a C3KX
Service Module installed) over a 30km distance where the measured insertion
loss makes ER transceivers marginal (total loss > 12dB) - so we're forced to
use ZR transceivers with their greater reach. As of the Aug 28th release of IOS
15.2(1)E the ZR optics are now supported in this switch - however our initial
testing using 3rd-party transceivers has been unsuccessful: we are unable to
get a link light on the port and the logical port never comes up when the fiber
is plugged in. I was hoping someone could help me sanity check the testing
methodology?
We're using 3rd-party SFP-10G-ZR clones that report VID: V01 to the switch.
They support DOM, and we've also tested LR transceivers from the same 3rd-party
successfully. My testing has been pretty simple so far:
Connect Tx-to-Rx and vice versa between the two transceivers using a 2m duplex
OS1 SMF patch lead that has 15dB fixed inline attenuators connected to bring
the received signal strength down to the supported range (-6 to -27 dBm)
Connected this way however we are unable to get a link light or port-up state
on these ports. The ZR transceivers show up in a "show inv" output, and the DOM
on the transceivers is reporting a valid strength Rx signal:
***********************************************************************switch1#sho
int te1/1/2 trans detailITU Channel not available (Wavelength not
available),Transceiver is internally calibrated.mA: milliamperes, dBm: decibels
(milliwatts), NA or N/A: not applicable.++ : high alarm, + : high warning, -
: low warning, -- : low alarm.A2D readouts (if they differ), are reported in
parentheses.The threshold values are calibrated.
[snip]
Optical High Alarm High Warn Low Warn Low Alarm
Transmit Power Threshold Threshold Threshold ThresholdPort (dBm)
(dBm) (dBm) (dBm) (dBm)--------- ---------------
---------- --------- --------- ---------Te1/1/2 1.7 4.7
4.0 0.0 -0.9 Optical High Alarm High
Warn Low Warn Low Alarm Receive Power Threshold Threshold
Threshold ThresholdPort (dBm) (dBm) (dBm) (dBm)
(dBm)------- --------------- ---------- --------- ---------
---------Te1/1/2 -12.2 -5.9 -7.2 -25.4
-27.2***********************************************************************
If we take the same patch cable, remove the attenuators and plug it into the
other LR transceivers in the same switches they get a link light instantly. I
realise these two sets of transceivers are operating at different frequencies
(1310nm vs 1550nm) but afaik an OS1 cable should be fine with both, right?
We've also swapped the ZR transceivers into the same ports the LRs are working
fine in, it makes no difference.
I'm afraid my own fiber knowledge is quite limited (much of it learned from
trying to troubleshoot this!), but can anyone suggest further troubleshooting
steps? We don't have the equipment to run an OTDR test on the patch leads, and
I'm trusting the DOM reporting to be at least vaguely accurate for signal
strength.
Thanks in advance for any assistance!
- J
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