This MIB module manages the service-aware feature of
Gateway GPRS Support Node (GGSN).
        
This MIB is an enhancement of the CISCO-GGSN-MIB. 
        
There needs to be a tight coupling between GGSN and CSG 
in order to realize the enhanced GGSN, which is capable 
of categorizing traffic flowing within a PDP context to
different services.
        
An enhanced version of Diameter Credit Control 
Application (DCCA) will be used for implementing  
real-time credit control of end users in the IPS 
framework.  The GGSN will act as DCCA client and will 
interact with DCCA server for quota negotiation and
usage reporting.
        
The credit control request (CCR) message is used between
DCCA-Client (DCCA-C) and DCCA-Server to request credit 
authorization for a given service.  The credit control 
request has one mandatory AVP (Attribute Value Pair) 
called CCR.  For a session based credit control 
several interrogation required, the first, intermediate
and final.  The first interrogation must be sent
before the DCCA-C allows any service event to the 
user, CCR type is set to INITIAL in this case.  When all
the granted service units for one unit type are spent
by the end user or the validity time is expired
the DCCA-C must send a new credit control (CC) request
to CC server, this is the intermediate interrogation
and the CCR type AVP is set to the value UPDATE. 
When the end user terminates a service session the 
DCCA-C must send a final CCR request message to the 
CC server.  The CCR type AVP is set to the FINAL 
or TERMINATION_REQUSET. 
        
CSG will be responsible for categorizing the traffic, 
quota management activities and usage reporting 
functions.  GGSN will act as a quota server for CSG. 
A proprietary interface based on GTP' will be used 
between GGSN and CSG.     
        
 Acronyms and terms:
        
 APN    Access Point Name
 CCA    Credit Control Answer
 CCR    Credit Control Request
 CCFH   Credit Control Failure  Handling
 CDR    Charging Data Record
 CLCI   Closed Loop Charging Interface
 CSG    Content Service Gateway
 DCCA   Diameter Credit Control Application
 ETSI   European Telecommunications Standards Institute
 GGSN   Gateway GPRS Support Node
 GPRS   General Packet Radio Service
 GSM    Global System for Mobile communication
 GTP    GPRS Tunneling Protocol
 MS     Mobile Station
 MSISDN Mobile Station ISDN number
 PDP    Packet Data Protocol
 PLMN   Public Land Mobile Network
 SGSN   Serving GPRS support Node
 SLB    Server Load Balancing
 TFT    Traffic Flow Template
 UMTS   Universal Mobile Telecommunications System
 QS     Quota Server
 UE     User Equipment
        
REFERENCE
        
[1] GSM 03.60: Digital cellular telecommunications
    system (Phase 2+); General Packet Radio Service
    (GPRS); Service description; Stage 2. V7.1.0
        
[2] GSM 09.60: Digital cellular telecommunication
    system (Phase 2+); General Packet Radio Service
    (GPRS); GPRS Tunnelling Protocol (GTP) across
    Gn and Gp Interface. V7.3.0
        
[3] 3GPP; Technical Specification Group Services
    and System Aspects; QoS Concept and Architecture.
    3G TS 23.107 v3.2.0.
        
[4] 3GPP; Technical Specification Group Core Network;
    General Packet Radio Service(GPRS); GPRS
    Tunnelling Protocol (GTP) across Gn and Gp
    Interface (Release 1999). 3G TS 29.060 v3.5.0.