03.603GPPGeneral Packet Radio Service (GPRS)Release 1998Service descriptionStage 2TS
For the purposes of the present document, the terms and definitions given in GSM 02.60 apply.
For the purposes of the present document the following abbreviations apply. Additional applicable abbreviations can be found in GSM 01.04 .
AA Anonymous Access
APN Access Point Name
ATM Asynchronous Transfer Mode
BG Border Gateway
BSSAP+ Base Station System Application Part +
BSSGP Base Station System GPRS Protocol
BVCI BSSGP Virtual Connection Identifier
CCU Channel Codec Unit
CDR Call Detail Record
CGF Charging Gateway Functionality
CGI Cell Global Identification
CS Circuit Switched
DNS Domain Name System
GGSN Gateway GPRS Support Node
GMM/SM GPRS Mobility Management and Session Management
GSN GPRS Support Node
GTP GPRS Tunnelling Protocol
ICMP Internet Control Message Protocol
IETF Internet Engineering Task Force
IHOSS Internet-Hosted Octet Stream Service
IP Internet Protocol
IPv4 Internet Protocol version 4
IPv6 Internet Protocol version 6
IPX Internet Packet eXchange
ISP Internet Service Provider
L2TP Layer‑2 Tunnelling Protocol
LL‑PDU LLC PDU
LLC Logical Link Control
MAC Medium Access Control
MNRF Mobile station Not Reachable Flag
MNRG Mobile station Not Reachable for GPRS flag
MNRR Mobile station Not Reachable Reason
MTP2 Message Transfer Part layer 2
MTP3 Message Transfer Part layer 3
NGAF Non-GPRS Alert Flag
NS Network Service
NSAPI Network layer Service Access Point Identifier
NSS Network SubSystem
P‑TMSI Packet TMSI
PCU Packet Control Unit
PDCH Packet Data CHannel
PDN Packet Data Network
PDP Packet Data Protocol, e.g., IP or X.25 
PDU Protocol Data Unit
PPF Paging Proceed Flag
PPP Point-to-Point Protocol
PVC Permanent Virtual Circuit
RA Routeing Area
RAC Routeing Area Code
RAI Routeing Area Identity
RLC Radio Link Control
SGSN Serving GPRS Support Node
SM Short Message
SM-SC Short Message service Service Centre
SMS-GMSC Short Message Service Gateway MSC
SMS-IWMSC Short Message Service Interworking MSC
SN‑PDU SNDCP PDU
SNDC SubNetwork Dependent Convergence
SNDCP SubNetwork Dependent Convergence Protocol
TCAP Transaction Capabilities Application Part
TCP Transmission Control Protocol
TID Tunnel Identifier
TLLI Temporary Logical Link Identity
TRAU Transcoder and Rate Adaptor Unit
UDP User Datagram Protocol
For the purposes of the present document, the following symbols apply:
Ga Charging data collection interface between a CDR transmitting unit (e.g., an SGSN or a GGSN) and a CDR receiving functionality (a CGF).
Gb Interface between an SGSN and a BSS.
Gc Interface between a GGSN and an HLR.
Gd Interface between a SMS-GMSC and an SGSN, and between a SMS-IWMSC and an SGSN.
Gf Interface between an SGSN and an EIR.
Gi Reference point between GPRS and an external packet data network.
Gn Interface between two GSNs within the same PLMN.
Gp Interface between two GSNs in different PLMNs. The Gp interface allows support of GPRS network services across areas served by the co-operating GPRS PLMNs.
Gr Interface between an SGSN and an HLR.
Gs Interface between an SGSN and an MSC/VLR.
kbit/s Kilobits per second.
R Reference point between a non-ISDN compatible TE and MT. Typically this reference point supports a standard serial interface.
Um Interface between the mobile station (MS) and the GPRS fixed network part. The Um interface is the GPRS network interface for providing packet data services over the radio to the MS. The MT part of the MS is used to access the GPRS services through this interface.