Cisco ASR 5000 Series Administration Manual page 62

▀ How GGSN Works
Figure 11. Non-Transparent IP Session Call Flow
1. The Mobile Station (MS) goes through the process of attaching itself to the GPRS/UMTS network.
2. The Terminal Equipment (TE) aspect of the MS sends AT commands to the Mobile Terminal (MT) aspect of the
MS to place it into PPP mode.
The Link Control Protocol (LCP is then used to configure the Maximum-Receive Unit size and the
authentication protocol (Challenge-Handshake Authentication Protocol (CHAP), Password Authentication
▄ Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide
GGSN Support in GPRS/UMTS Wireless Data Services
OL-22944-02