A GPRS Support Node (GGSN) has a plurality of slave data session control units (GTP-C/s) for controlling data sessions for Mobile Stations (MSs), a plurality of data sessions payload units (GTP-Us) for supporting routing of data sessions payloads, and a master data session control unit (GTP-C/m) dispatching...http://www.google.de/patents/US20030117948?utm_source=gb-gplus-sharePatent US20030117948 - Method and gateway GPRS support node (GGSN) for control plane redundancy
