User`s guide

172 Chapter 4
Functionality/Operation
GPRS Overview
PSPDN: Packet Switched Public Data Network
PSTN: Public Switched Telephone Network
SGSN: Serving GPRS Support Node
The BSC has a second path to choose from when sending and receiving user data.
Voice: Sent to the MSC
GPRS data: Sent to the Serving GPRS Support Node (SGSN)