i have 2 nec systems that have when we switched
from copper trunks to "fiber to the premise"
the caller id quit working.
I hear the data burst between the 1st and 2nd ring
cycle but the system doesn't hear/see the caller id or just doesn't pass it.
I can hook the old copper back up and it works good.

Any particular specs for caller id i should look at?

IS this supposed to be "dtmf" caller id or is it "fsk"?

Any help would be appreciated