In a shared-tenant services arrangement, numbering-plan independence and cross-plan access is provided to tenant groups by a call-processing arrangement (200) that stores separate definitions of both syntax (320, 350) and grammar (400, 410) of each group's own extension numbering plan. In response to...http://www.google.de/patents/US5321743?utm_source=gb-gplus-sharePatent US5321743 - Shared-tenant services arrangement providing numbering-plan independence and cross-plan access to tenant groups
