the nec is a little different than nortel/avaya/lucent/at&t (or whatever their name is this week)
it sounds like the lines do NOT appear on the phones.
on the above if a line doesn't appear on the phone it "lands" on the intercom keys. NOT SO with the nec! it needs some place to "land" the call. in the nec world it is called cap (short for call appearance) keys.
some more reading here:
https://www.sundance-communications.com/forum/Forum14/HTML/000075.html https://www.sundance-communications.com/forum/Forum14/HTML/000482.html the trunks (by default unless someone changed it) should have already been in trunk group 1 (dial 9). this is program 3-03
now you'll have to either assign all of the lines to all of the phones OR use cap keys, or a combo of both.
if you go the cap keys route, you'll need to know that if someone puts a call on line 1 on hold the other phones with cap keys do not see it! the call will have to be parked or transferred to the ext needed.
