Cisco Cisco Packet Data Interworking Function (PDIF) 故障排查指南
GGSN Support in GPRS/UMTS Wireless Data Services
▀ Features and Functionality - Optional Enhanced Feature Software
▄ Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide
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augmented by additional features such as 800 RADIUS Server Groups to permit use of enterprise controlled AAA
servers and custom dictionaries.
servers and custom dictionaries.
Session Recovery Support
The Session Recovery feature provides seamless failover and reconstruction of subscriber session information in the
event of a hardware or software fault within the system preventing a fully connected user session from being
disconnected.
event of a hardware or software fault within the system preventing a fully connected user session from being
disconnected.
Session recovery is performed by mirroring key software processes (e.g. session manager and AAA manager) within the
system. These mirrored processes remain in an idle state (in standby-mode), wherein they perform no processing, until
they may be needed in the case of a software failure (e.g. a session manager task aborts). The system spawns new
instances of “standby mode” session and AAA managers for each active Control Processor (CP) being used.
system. These mirrored processes remain in an idle state (in standby-mode), wherein they perform no processing, until
they may be needed in the case of a software failure (e.g. a session manager task aborts). The system spawns new
instances of “standby mode” session and AAA managers for each active Control Processor (CP) being used.
Additionally, other key system-level software tasks, such as VPN manager, are performed on a physically separate
packet processing card to ensure that a double software fault (e.g. session manager and VPN manager fails at same time
on same card) cannot occur. The packet processing card used to host the VPN manager process is in active mode and is
reserved by the operating system for this sole use when session recovery is enabled.
packet processing card to ensure that a double software fault (e.g. session manager and VPN manager fails at same time
on same card) cannot occur. The packet processing card used to host the VPN manager process is in active mode and is
reserved by the operating system for this sole use when session recovery is enabled.
The additional hardware resources required for session recovery include a standby System Processor Card (SPC) and a
standby packet processing card.
standby packet processing card.
There are two modes for Session Recovery.
Task recovery mode: Wherein one or more session manager failures occur and are recovered without the need
to use resources on a standby packet processing card. In this mode, recovery is performed by using the
mirrored “standby-mode” session manager task(s) running on active packet processing cards. The “standby-
mode” task is renamed, made active, and is then populated using information from other tasks such as AAA
manager.
mirrored “standby-mode” session manager task(s) running on active packet processing cards. The “standby-
mode” task is renamed, made active, and is then populated using information from other tasks such as AAA
manager.
Full packet processing card recovery mode: Used when a packet processing card hardware failure occurs, or
when a packet processing card migration failure happens. In this mode, the standby packet processing card is
made active and the “standby-mode” session manager and AAA manager tasks on the newly activated packet
processing card perform session recovery.
made active and the “standby-mode” session manager and AAA manager tasks on the newly activated packet
processing card perform session recovery.
Session/Call state information is saved in the peer AAA manager task because each AAA manager and session manager
task is paired together. These pairs are started on physically different Ppacket processing cards to ensure task recovery.
task is paired together. These pairs are started on physically different Ppacket processing cards to ensure task recovery.
I
MPORTANT
:
For more information on this feature, refer Session Revocery chapter in System Enhanced Feature
Configuration Guide.
Traffic Policing and Rate Limiting
Allows the operator to proportion the network and support Service-level Agreements (SLAs) for customers.
The Traffic-Policing/Shaping feature enables configuring and enforcing bandwidth limitations on individual PDP
contexts of a particular 3GPP traffic class. Values for traffic classes are defined in 3GPP TS 23.107 and are negotiated
with the SGSN during PDP context activation using the values configured for the APN on the GGSN. Configuration and
enforcement is done independently on the downlink and the uplink directions for each of the 3GPP traffic classes.
contexts of a particular 3GPP traffic class. Values for traffic classes are defined in 3GPP TS 23.107 and are negotiated
with the SGSN during PDP context activation using the values configured for the APN on the GGSN. Configuration and
enforcement is done independently on the downlink and the uplink directions for each of the 3GPP traffic classes.