Light levels with ZX SFP's

[Rick Hornung]

I have 4 GLC-ZX-SMD SFP's between two Cisco IE4000's, everything came up fine but ovenright I lost light and link.  On one side I can still see -8.9db, but it's -40 on the other.  My span loss OTDR'd out at 9db of loss not including my fiber patch cables, from what I found online I need at least 8 db of loss before I have to use an atenuator.  I figure with span loss of 9db plus some loss with patching I was safe, and I was showing -9db on one side and -8.9 on the other, did I burn up these SFP's?

[Tom Randstrom]

Based on your link insertion loss, it doesn't seem it would be receiver burn out, given the ZX spec is -3dBm max input power (and you indicated -8.9 and -9 dBm on this link). Possibly just infant mortality of the SFP.

[Rick Hornung]

Turns out we had a parital break in the fiber