Dynamic Ip Address Assignment - Cisco ASR 5000 series Product Overview

▀ How GGSN Works
Important:
configured locally on the system.
Dynamically :The APN template can be configured to dynamically assign an IP address from locally
configured address pools or via a Dynamic Host Control Protocol (DHCP) server. Additional information on
dynamic address assignment can be found in the Dynamic IP Address Assignment section that follows.
Selection mode: The MS's right to access the APN can be either verified or unverified. For verified access, the
SGSN specifies the APN that should be used. For unverified access, the APN can be specified by either the
SGSN or the MS.
Timeout: Absolute and idle session timeout values specify the amount of time that an MS can remain connected.
Mobile IP configuration: Mobile IP requirements, HA address, and other related parameters are configured in
the APN template.
Proxy Mobile IP support: Mobile IP support can be enabled for all subscribers facilitated by the APN.
Alternatively, it can be enabled for individual subscribers via parameters in their RADIUS or local-user
profiles.
Quality of Service: Parameters pertaining to QoS feature support such as for Dynamic Renegotiation, Traffic
Policing, and DSCP traffic class.
A total of 11 PDP contexts are supported per subscriber. These could be all primaries, or 1 Primary and 10 secondaries
or any combination of primary and secondary. Note that there must be at least one primary PDP context in order for
secondaries to come up.

Dynamic IP Address Assignment

IP addresses for PDP contexts can either be static—an IP address is permanently assigned to the MS—or dynamic—an
IP address is temporarily assigned to the MS for the duration of the PDP context.
As previously described in the PDP Context Processing section of this chapter, the method by which IP addresses are
assigned to a PDP context is configured on an APN-by-APN basis. Each APN template dictates whether it will support
static or dynamic addresses. If dynamic addressing is supported, the following methods can be implemented:
Local pools: The system supports the configuration of public or private IP address pools. Addresses can be
allocated from these pools as follows:
Dynamic Host Control Protocol (DHCP): The system can be configured to use DHCP PDP context address
assignment using either of the following mechanisms:
▄ Cisco ASR 5000 Series Product Overview
Static IP addresses configured in subscriber profiles must also be part of a static IP address pool
Public pools: Provided that dynamic assignment is supported, a parameter in the APN configuration
mode specifies the name of the local public address pool to use for PDP contexts facilitated by the
APN.
Private pools: Provided that dynamic assignment is supported, the name of the local private pool can
be specified in the subscriber's profile. The receipt of a valid private pool name will override the
APN's use of addresses from public pools.
GGSN Support in GPRS/UMTS Wireless Data Services
OL-22938-02