A synchronous optical network (SONET) system having multi-hierarchal
network service access point (NSAP) addressing includes electrically
linked network elements (NEs) and first and second level routing areas
which each include at least one NE. The NEs include devices having
respective NSAP addresses and at least one of the NEs is a network
controller that controls the SONET. The first level routing area and the
second level routing areas are based on a predetermined prioritization of
the NEs as first level NEs and second level NEs, and have a first level
routing and having a second level routing for the NSAP addresses,
respectively. Each NSAP address includes a Routing Domain field and an
Area field filled with information indicative of a respective Internet
Protocol (IP) address.