Cisco Cisco Packet Data Gateway (PDG) Fehlerbehebungsanleitung
Ty Interface Support
How it Works ▀
Cisco ASR 5000 Series Enhanced Feature Configuration Guide ▄
OL-22982-01
How it Works
This section describes the IMS authorization and dynamic policy support in a cdma2000 networks.
The DPCA is the Ty interface to the Policy Control and Charging Rule Function (PCRF). The PCRF contains both PDF
(Policy Decision Function) and CRF (Charging Rule Function). The PCRF may reside in Proxy-Call Session Control
Function (P-CSCF) or on stand-alone system.
(Policy Decision Function) and CRF (Charging Rule Function). The PCRF may reside in Proxy-Call Session Control
Function (P-CSCF) or on stand-alone system.
The interface between IMSA with PCRF is the Ty interface and between Session Manager and Online Charging Service
(OCS) is the Tx interface.
(OCS) is the Tx interface.
Important:
Online charging is not supported in this release.
Ty Interface Support with AGW
IMS authorization support performs in following way to provide the IMS authorization service to a subscriber in
cdma2000 network.
cdma2000 network.
When an AGW receives a packet in downlink or uplink direction, it matches the packets against all the downlink/uplink
PCC rules that configured by the PCRF for the subscriber. On the basis of matching rules it selects one PCC rule and
applies the ‗gating policy‘ as available in selected PCCC rule to the flow. It also applies the traffic policing to the flow
on the basis of downlink/uplink bandwidth limit provided in authorized QoS profile available in the PCC rule. To
provide the bandwidth limit the AGW uses 3 color 2 bucket in the color blind mode to enforce the bandwidth.
PCC rules that configured by the PCRF for the subscriber. On the basis of matching rules it selects one PCC rule and
applies the ‗gating policy‘ as available in selected PCCC rule to the flow. It also applies the traffic policing to the flow
on the basis of downlink/uplink bandwidth limit provided in authorized QoS profile available in the PCC rule. To
provide the bandwidth limit the AGW uses 3 color 2 bucket in the color blind mode to enforce the bandwidth.
If flow is in uplink direction AGW applies the routing function on the packet or extract the flow-identifier for the
downlink flow with the use of Flow-Identifier AVP in PCC rule.
downlink flow with the use of Flow-Identifier AVP in PCC rule.
Based on the flow -id the AGW selects the A10 to transport the packet and adds the flow identifier attributes to the GRE
header and forwards the packet on the selected A10.
header and forwards the packet on the selected A10.
The following figure provides a high-level view of the IMS authorization process between a system and IMS
components that is initiated by the MN. The table explains each step in detail.
components that is initiated by the MN. The table explains each step in detail.
Note that the IMS Authorization (IMSA) service and Diameter Policy Control Application (DPCA) are part of Session
Manager on the system and separated in the following figure for illustration purpose only.
Manager on the system and separated in the following figure for illustration purpose only.