3G challenges to WAP Gateway performance and Solutions

Role of WAP Gateway in Data Service

WAP Gateway plays a very important role in data services. It is an important bridge between wireless terminals and the Internet world. With the user terminal and Network Environment
As well as the continuous development of Internet technology, the development of WAP has also gone through wap1.0, wap1.1, and wap1.2 until today's WAP2.0. However
The WAP communication model remains unchanged, but the functions of each component in the WAP system have changed. Taking wap1.x as an example, the WAP communication model is shown in:

The application model shows that the WAP communication model is similar to that of www. WAP also uses the client/server communication model, but the biggest difference between the two is that between the client and the server, a WAP Gateway is added. The WAP terminal communicates with the application server through the WAP Gateway, which is similar to the WWW method. clients in the LAN access the Internet through the proxy server. Throughout the process, the WAP gateway not only acts as a request proxy, but also provides the following functions:

(1) protocol conversion function: Translation of requests from the WAP protocol to the WWW protocol, and vice versa;

(2) content encoding/decoding, format conversion, and content compression functions to reduce the amount of data transmitted over the wireless data network.

After WAP2.0, as the WAP protocol stack introduced a dedicated WP-TCP and WP-HTTP for wireless environment optimization, as well as support for end-to-end security TLS protocol
Added support for XHTML/CSS at the layer. Therefore, theoretically, the terminal can access internet resources without the WAP Gateway from a technical point of view. However, if
From the perspective of this, the WAP Gateway still has to exist, but its protocol conversion function is weakened, and its main function becomes request proxy and content conversion and compression. In addition, the WAP gateway must provide user authentication and access control.
System, business statistics, and other operational functions. Of course, the Protocol Conversion Function of the WAP gateway must be retained to support the existing wap1.x end users.

3G challenges to WAP Gateway

Before the arrival of 3G, the development of data services was severely affected by factors such as terminal capabilities, wireless bandwidth, communication charges, and incomplete WAP protocols. Users who use data services do not
And there are not many available data services. Therefore, the performance requirements for WAP gateways are not high. Taking China Mobile as an example, the processing capacity of the WAP Gateway in general provinces is 3000
Below TPS, the processing capacity of WAP Gateway is only below 10000 TPS in a few provinces with better data service development.

However, with the arrival of 3G, the above unfavorable factors for the development of data services are gradually being resolved. From the user's point of view, 3G brings us more and more diversified data services
Fast Internet access and cheaper communication fees. Even on the eve of 3G, the development trend of data services has exploded ahead of schedule. This can be evidenced by the data released by the recent application vendors.
Ming. From a technical perspective, many of these services must rely on WAP gateways. Therefore, this puts forward higher requirements on the performance of the WAP Gateway.

Countermeasures for ZTE's WAP Gateway Products

To improve the performance, you must first analyze the network structure of the WAP Gateway product in the current network and the business process of the current network to find out the performance bottleneck. Business-related components of the WAP Gateway products on the current network are service processors and RADIUS servers. Generally, service processors use layer-4 switches to achieve load balancing, while RADIUS servers generally use the Master/Slave Mode.

In the above network structure, as long as the performance of the layer-4 Switching product is good enough, the problem of service processing capability can be solved by increasing the number of processors. Therefore, the overall performance bottleneck of the WAP Gateway is on the RADIUS server.

The reason why the RADIUS server cannot achieve dynamic expansion and load cluster through a simple layer-4 switch product like the service processor is determined by the existing business process. The existing business flow requires end users to send a radius billing request to the WAP Gateway before accessing the application. The RADIUS server of the WAP gateway will save information such as the user's terminal number and IP address correspondence, used to process subsequent business requests (billing, authentication, etc ). If a layer-4 switch is used to implement a radius cluster, the business processor cannot know which RADIUS server should be used to find information such as the correspondence between the number and IP address of an end user.

To solve this problem, zxme WAP, a WAP Gateway product of ZTE, uses the following radius cluster solution without changing the existing business process.

The zxme WAP radius cluster solution consists of the radius distribution server and the radius processing server. The Radius Distribution server adopts the dual-host master-slave structure, and the radius processing server uses the cluster mode. Shows the specific networking:

The specific implementation process is described as follows:

1,
After receiving the radius billing package (Start and Stop messages) sent from ggsn, pdsn, and AAA to the WAP gateway, the radius distribution server follows a certain dynamic load balancing algorithm.
(For example, the simplest round-robin mechanism), distribute these packets to a radius processing server. Note: The radius billing package is not unwrapped here.

2. After the radius processing server receives the radius packet forwarded by the Radius Distribution server, it completes packet parsing and maps the radius response message, IP address, and mobile phone number, and other attributes required by subsequent business processes are sent to the radius distributor.

3. The Radius Distribution server saves the IP address and mobile phone number ing information and other attributes required by subsequent business processes (such as APN and bearer type ).

4. When the WAP service processing server receives a WAP service request forwarded by ggsn, It queries the mobile phone msisdn number corresponding to the IP address and other attributes on the Radius Distribution server.

In this solution, the radius distribution server does little work and its functions consume little resources, however, the most resource-consuming features of radius message processing, as well as subsequent processing, are distributed to various radius processing machines for execution, which greatly improves the overall system performance, the test results also verify the feasibility and effectiveness of this solution.

 

Source: China Information Industry Network