I have the same problem on my site having unknown number from meridian to cisco side using PRI.. Site 1 is nortel, site 2 is cisco and site 3 also nortel..when site 1 or site call they can see the name display and the calling number, site 2 & 3 they can see also, but site 1 can't see the number and name display (unknown number) if the site 3 make a call to site 1 but if site 1 make a call to sit 3 there is no problem.