ETSI TS 101 297 Digital cellular telecommunications system (Phase 2+) (GSM); General Packet Radio Service (GPRS); Mobile Station (MS) - Serving GPRS Support Node (SGSN); Subnetwork Dependent Convergence Protocol (SNDCP) (GSM 04.65 version 7.1.1 Release 1998)

standard by European Telecommunications Standards Institute, 11/01/1999