Gy Interface Support - Cisco ASR 5000 series Product Overview

▀ Accounting Interfaces

Gy Interface Support

Important:
The Gy interface provides a standardized Diameter interface for real-time content-based charging of data services. It is
based on the 3GPP standards and relies on quota allocation.
It provides an online charging interface that works with the ECS Deep Packet Inspection feature. With Gy, customer
traffic can be gated and billed in an ―online‖ or ―prepaid‖ style. Both time- and volume-based charging models are
supported. In all these models, differentiated rates can be applied to different services based on shallow or deep-packet
inspection.
Gy is a Diameter interface. As such, it is implemented atop, and inherits features from, the Diameter Base Protocol. The
system supports the applicable base network and application features, including directly connected, relayed or proxied
DCCA servers using TLS or plaintext TCP.
In the simplest possible installation, the system will exchange Gy Diameter messages over Diameter TCP links between
itself and one ―prepay‖ server. For a more robust installation, multiple servers would be used. These servers may
optionally share or mirror a single quota database so as to support Gy session failover from one server to the other. For a
more scalable installation, a layer of proxies or other Diameter agents can be introduced to provide features such as
multi-path message routing or message and session redirection features.
Gy interface is the reference point between Diameter server and GGSN for online accounting and charging through
Diameter based protocol. The Diameter server functions as Online Charging Service (OCS) and provides the online
charging data to the GGSN, which acts as a Charging Data Function (CDF). Connection between Diameter Client
(Diabase) and OCS is maintained by underlaying TCP connection of Diameter based protocol and exchanges a series of
messages to check the status of the connection and capabilities.
The Diameter Credit Control Application (DCCA) which resides as part of the ECS manages the credit and quota for a
subscriber.
The following figure depicts a typical Gy interface implementation between GGSN (CDF) and Diameter server (OCS)
with ECS.
Figure 183. Logical Online Charging with Gy Interface
GGSN (CDF)
ECSv2
DCCA
GGSN running ECS
▄ Cisco ASR 5000 Series Product Overview
This feature is only available in GGSN/UMTS networks.
DIABASE
Gy Interface
Server (OCS)
Enhanced Charging Service Overview
Diameter
OL-22938-02