Cisco Cisco Packet Data Gateway (PDG) Guía Para Resolver Problemas
L2TP Access Concentrator
▀ Supported LAC Service Configurations for the GGSN
▄ Cisco ASR 5000 Series Enhanced Feature Configuration Guide
OL-22983-01
The APN configuration indicates such things as the IP address of the LNS, the system destination context in which a LAC
service is configured, and the outbound username and password that will be used by the LNS to authenticate incoming
sessions. If no outbound information is configured, the subscriber‘s International Mobile Subscriber Identity (IMSI) is
used as the username at the peer LNS.
service is configured, and the outbound username and password that will be used by the LNS to authenticate incoming
sessions. If no outbound information is configured, the subscriber‘s International Mobile Subscriber Identity (IMSI) is
used as the username at the peer LNS.
1. The GGSN returns an affirmative Create PDP Context Response to the SGSN over the Gn interface.
2. The GGSN passes data received from the MS to a LAC service.
3. The LAC service encapsulates the IP packets and forwards it to the appropriate Gi interface for delivery to the
2. The GGSN passes data received from the MS to a LAC service.
3. The LAC service encapsulates the IP packets and forwards it to the appropriate Gi interface for delivery to the
LNS.
4. The LNS un-encapsulates the packets and processes them as needed. The processing includes IP address
allocation.
Non-transparent IP PDP Context Processing with L2TP Support
The following figure and the text that follows describe how non-transparent IP PDP contexts are processed when L2TP
tunneling is enabled.
tunneling is enabled.
Figure 31. Non-transparent IP PDP Context Call Processing with L2TP Tunneling