The Zone Default number is like an MSC (Mobile Switching Center) default for GSM (Global System for Mobile
Communication). Because there are normally numerous zones off of one GSM MSC and the coverage area for a GSM
switch can be enormous, it is necessary to have individual defaults for each zone, instead of a single number for all of
the zones off the switch. The Zone Default can be found in the GSMZONE table. If the carrier chooses, one number can
be used for the entire switch and it is provisioned in the GSMMSC table. The Zone Default is used if a cell site is not
provisioned.