This section describes the GTP' agent. This is a collection agent for real-time workflow configurations.

The GTP' agent collects messages and datagrams with charging protocol of type GTP' from GSM agents. By collecting this information the GTP' agent enables  to act as a Charging Gateway device, providing Charging Gateway Functionality (CGF) within UMTS/GPRS networks.

UMTS/GPRS Charging Gateway Functionality is Supported

The GTP' agent awaits initialization from the GSN nodes of the types SGSN and GGSN. When initiated, there are two protocols with which the Agent can interact with the nodes:

• Transmission Control Protocol(TCP), and

• Datagram Protocol(UDP)

A GTP' workflow can alternate implementation of two different protocols by using two GTP' agents. One for each protocol.

In case of failure, the GTP' agent can be configured to notify the GSN nodes to route the incoming data to another host. An alternative configuration is to set up a second and identical workflow, on a separate EC. The agent counts the received requests and publishes those values as MIM values. Those MIM values can also be viewed from the commandline tool with the wfcommand printcounters command.

The GTP' agent supports IPv4 and IPv6 environments.

Interaction Scenario

The following scheme demonstrates the message and data transfer between the GSN nodes and the GTP' agent when using UDP:
 

1. When started, the GTP' agent sends a Node Alive Request message to all configured GSN nodes.
    

2. The GTP' agent awaits a Node Alive Response and will transmit Node Alive Request repeatedly, according to the Advanced tab settings. For further information see Advanced Tab in GTP' Agent Configuration(3.3).
    

3. After a successful Node Alive Response the GSN node starts to transmit Data record Transfer Requests to the agent. When safely collected, the agent replies with a Data record transfer Response.
    

4. When the workflow is stopped, the message Redirection Request is automatically sent to all configured GSN nodes. The workflow will not stop immediately, but waits for a Redirection Response from each of the GSN nodes. If the Max Wait for a Response (sec) value is exceeded, the workflow stops, regardless of whether Redirection Response from the GSN nodes has been received or not.

   Note!

   When using TCP, the behavior is different. For further information see GTP' Agent MZSH Commands, Events and Limitations(3.3).

Prerequisites

The reader of this information should be familiar with:

• GPRS Tunneling Protocol (GTP) across the Gn and Gp Interface [3GPP TS 29.060 V4.2.0]:http://www.3gpp.org/ftp/Specs/archive/29_series/29.060/29060-420.zip

The section contains the following subsections:

• GTP' Agent Preparations(3.3)
• GTP' Agent Configuration(3.3)
• GTP' Agent Input/Output Data and MIM(3.3)
• GTP' UDR(3.3)
• GTP' Agent MZSH Commands, Events and Limitations(3.3)
• Handling of UDP Traffic for GTP' Agent(3.3)