Are these all local calls or a mix of local and LD? Are the mobile phones all on the same carrier or different? What is the configuration of the Cisco and Nortel systems? Are you sending calls from Cisco to Nortel and then out to the world, or how? If they all go through the Nortel, do you have PRI circuits that you can monitor the D Channel to see what the system is sending out for each type of call? You can do the same thing on your qsig trunk to see if the number is even passing from Cisco to Nortel if that is the way it is set up.