Browse Prior Art Database

3GPP GTP' Flow Control

IP.com Disclosure Number: IPCOM000010692D
Original Publication Date: 2003-Jan-08
Included in the Prior Art Database: 2003-Jan-08
Document File: 2 page(s) / 112K

Publishing Venue

Motorola

Related People

Rob Curtis: AUTHOR [+2]

Abstract

The GPRS Tunneling Protocol (GTP’) defined by 3GPP and used for signaling on the Ga interface currently does not possess a robust flow control mechanism. In the latest specification, GTP’ message buffering and/or rerouting only occurs following an error condition. In this paper we propose a sliding window to facilitate flow control in an arbitrary network configuration. Detection of a zero width window size enables source nodes to switch to an alternate destination. Detection of a non-zero width window size enables source nodes to revert back to the original destination node. Improved handshaking reduces undesirable behavior during heavy traffic periods and more efficiently utilizes network CPU, link and buffer resources.

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3GPP GTP’ Flow Control[MP1] 

By Rob Curtis, Pranavkumar Joshi

Motorola, Inc.

Global Telecom Solutions Sector

 

ABSTRACT

The GPRS Tunneling Protocol (GTP’) defined by 3GPP and used for signaling on the Ga interface currently does not possess a robust flow control mechanism.� In the latest specification, GTP’ message buffering and/or rerouting only occurs following an error condition.� In this paper we propose a sliding window to facilitate flow control in an arbitrary network configuration.� Detection of a zero width window size enables source nodes to switch to an alternate destination.� Detection of a non-zero width window size enables source nodes to revert back to the original destination node. Improved handshaking reduces undesirable behavior during heavy traffic periods and more efficiently utilizes network CPU, link and buffer resources.

PROBLEM

The GPRS Tunneling Protocol (GTP’) defined by 3GPP and used for signaling on the Ga interface currently does not possess a robust flow control mechanism.� In the latest specification, GTP’ message buffering and/or rerouting only occurs following an error condition. This mode of operation can result in undesirable behavior in heavy traffic periods.� During such peak load occurrences when load shedding is necessary, destination nodes need to do more than ignore incoming messages; improved handshaking is required to avoid instability.� With such enhancements, utilization of many network resources (e.g., CPUs, links and buffers) will also be made more efficient.

SOLUTION

In this paper, we propose a sliding window mechanism for flow control between a multiplicity of source and destination nodes.� The solution provides an efficient means of triggering message transmission to an alternate destination in the pool when a given node becomes unavailable.� Reception of a zero width window size directs source nodes to halt message transmission until further notice while also enabling a clean redirection to a different destination if desired.� Reception of a non-zero width window size enables source nodes to resume message transmission or revert back to original destination node.� In addition to this type of binary flow control, a non-zero, but small, window size can also be used following a destination node restart to throttle backlogged traffic backlogged in many source nodes.

OPERATION

Figure 1 illustrates the preferred embodiment of the solution per [1].� Various GPRS Support Nodes (GSNs) operate as GTP’ message sources.� GTP’ messages are generated as a result of a variety of GPRS radio network event processing tasks.� A pool of Charging Gateway Functions (CGFs) serve to receive and process GTP’ messages containing Call Detail Records (CDRs) of charging and event data.� CGFs perform pre-processing functions before the CDRs are transferred to the billing system.

Figure 1

Figure 2

As shown in Figure 2, to implement the proposed flow control, the Data Record Transfer Request message is enhanced...