This MIB module manages the client side
functionality of the Persistent Storage Device(PSD).

This MIB instrumentation is for configuring
data-store(PSD client) feature on GGSN and monitoring
the state of the PSD server(up/down/full).

The Cisco Persistent Storage Device(PSD) is an
extension to existing storage on the Cisco Content
Services Gateway(CSG).

The GGSN currently allows sending of the CDRs to an
active CG, while allowing up to two standby CG's to
be configured. When all the configured CG's become
unavailable, the CDRs get stored at the GGSN and
start using up GGSN resources such as memory. As the
amount of memory is limited on GGSN and failure of
GGSN shall lead to losing these stored CDRs.
Using PSD as temporary storage, shall avoid losses
due to these problems. When all the configured CG's
are unavailable, GGSN needs to backup the live closed
CDR's to a PSD. When any of the CG's shall become
available, GGSN shall retrieve the stored CDR's
automatically from the PSD and forwards them to the
active CG.

PSD supports the charging protocol(GTP'), version 0 
with a few private extensions, which is used to
facilitate the required functionality via UDP.

Acronyms and terms:

  CDR    Call Detail Record
  CID    Charging Identification
  CG     Charging Gateway
  CGF    Charging Gateway Functionality
  DS     Data-Store
  ETSI   European Telecommunications Standards
         Institute
  Ga     Name of the interface between SGSN/GGSN and
         CG
  Gi     Name of the interface between GGSN and PDN
  Gn     Name of the interface between GGSN and SGSN
  G-CDR  Gateway GPRS Support Node-Call Detail Record
  GGSN   Gateway GPRS Support Node
  GPRS   General Packet Radio Service
  GSM    Global System for Mobile communication
  GTP    GPRS Tunneling Protocol
  GTP'   GTP enhanced for charging
  IE     Information Element
  MS     Mobile Station
  PDN    Packet Data Network
  PDP    Packet Data Protocol
  SGSN   Serving GPRS support Node
  TOS    Type of Service.
  PSD    Persistence Storage Device.