[c-nsp] Attenuate me...

[Robert E.Seastrom]

I've got a couple of e0 OC12 IR POS cards in routers in adjacent racks
(don't laugh, they were cheap!) talking to each other over a 4m long
chunk of SM fiber.  Getting errors out the wazoo.  At a guess, I'm
probably overdriving the receiver.

Can anyone suggest an appropriate value for attenuators for this kind
of configuration?  Docs I've seen suggest that this should work, but
barely, with no attenuators...  what do people find works in practice?
6 dB?  10 dB?

Thanks,
                                        ---Rob