Architecture Proposal for an Internet Services Charging Platform

Transcription

1 Internal Working Paper Architecture Proposal for an Internet Services Charging Platform John Cushnie Distributed Multimedia Research Group, Lancaster University, UK. Abstract. This short paper proposes a Charging Platform architecture for support of Internet charging and billing research. The proposed Charging Platform allows for the development and automated running of networked experiments, and the collection and presentation of results using the World Wide Web medium. The proposal is described in terms of the software and hardware required, with example test scenarios and a discussion of what may be achieved with such an approach. 1. Introduction Charging, billing and for the Internet have been identified as important research areas by many organisations over the past years, leading to many excellent publications, conferences and workshops [Clark, COST263, McKnight, Shenker], and much debate over the how s and why s. There is great scope for investigation of novel and innovative charging mechanisms for Internet access, services and applications, in addition to evaluations of already proposed protocols and methods. There are also actions currently ongoing in the IETF [IETF] and IRFT [IRTF] to propose and evaluate architectures for Authentication Authorisation & Accounting (AAA) [AAA] in the Internet both for the short and long term. In order to carry out detailed technical research into charging and billing mechanisms for the Internet, including implementation and/or evaluation of AAA architectures, a basic infrastructure is required for the collection and analysis of data. A platform is also required to develop and build the software required to implement the charging mechanisms and charging models being researched. This paper proposes the technical architecture for a Charging Platform to meet this requirement.

2 2. Application Requirements The Charging Platform being proposed is seen to be a repository for test cases and test data and also as an automated test system that may schedule short or long term tests and experiments. The Charging Platform will also assimilate and present test results in a number of formats. The favoured means of data and results presentation is the Web browser paradigm with hyperlink functionality to ease navigation of the potentially large amounts of data. This will also allow the download of test data and results for inclusion in test reports and research papers. A proposed architecture for the Charging Platform is shown in Figure 1. PHP & Perl Scripts MySQL Database Scripts Data Source Code EXEs Results Queries Control Web Based Interface Apache Web Charging Platform Results Reports Graphs... Network (eg IP-Multicast GCAP) Figure 1 Proposed Charging Platform Architecture Commercial billing systems for telephony and data networks are based around robust industry standard relational databases, such as Oracle or Informix, appropriate to the high volumes of data involved and the data processing required. To implement a suitable Charging Platform to support research work in charging and billing the use of a quality database to collate test data and results is considered essential. A further requirement is the availability of tools for information and data processing, such as scripting languages, for rapid development of software support to the manipulate captured data and results. The primary aim is to use the Charging Platform to research possible charging and billing mechanisms that are applicable to (but not limited to) IPv6 [IPv6], WAP [WAP], GPRS [Cai], UMTS [UMTS] and IP-Multicast, for example GCAP [GCAP]. The investigation of charging models for Internet usage is also an important research area [Cushnie] that may be supported by the Charging Platform, including the application to mobile/wireless and fixed Internet networks. 2

3 3. System Specification The proposed Charging Platform is based around the standard RedHat [RedHat] Linux server running free Open Source software. Linux is the operating system of choice for the Charging Platform as it provides the best support in terms of stability and speed of execution for the Open Source software specified later in this paper. Linux also provides a multitasking environment that is required if the Charging Platform is to be used by more than one researcher or experiment concurrently. Some of the proposed Open Source software has been tried out on the Microsoft Windows NT/98 operating systems with varying amounts of success. Most of the Windows versions of the Open Source software are still in beta test form and therefore should not be used in live or production environments, without due care and attention. The preferred hardware platform is an Intel Pentium PC, since this offers the most compatibility with the Linux operating system. Although there are Linux ports to other hardware platforms, e.g. Sun Sparc, they are not the mainstream of the Linux community effort and the level of support is usually compromised as a result. The building of the Charging Platform on the Linux operating system also has the advantages of stability, support for industry standard communication protocols, user community support and large software application base. Therefore Linux may be considered a low risk platform for this kind of development. Open Source Software Applications To achieve openness for this implementation and to make use of free software available this proposal is based on Open Source software applications, and does not include any proprietary or commercial software. The following notes discuss the Open Source software being proposed for the Charging Platform with any additional notes as required. Apache Webserver [Apache] The Apache webserver is to be used to provide the hosting of webpages, both static and dynamic from the Charging Platform. This is the defacto Webserver in use today on the Internet, and has a reputation for robustness and stability, as well as good support for integration with other Open Source software - compatibility with Perl and php are strong points of this software. Perl [Perl] This is the defacto scripting language on the Linux, Unix and the World-Wide-Web Internet. Example Perl programs and functions are widely available and the language is very popular, especially for text and data processing applications. Perl may be used stand alone or integrated with the Webserver. Either way it provides a very powerful programming environment suited 3

4 to rapid development and deployment. Perl may also be used to generate dynamic Webpages via the Webserver when used as a server-side scripting language. php HyperText PreProcessor [php] This software allows the dynamic generation of Webpages from within HTML pages, in a similar way to Perl, as a server-side scripting language. Unlike Perl, php code can be directly embedded into HTML code and automatically executed via a suitably configured web server. It may also be used standalone in the same way as Perl. Php also has further advantage with a direct API interface built in for the MySQL database engine. Php already has a high profile corporate user-base including NASA and Sony Music. MySQL Relational Database [MySQL] This software offers the functionality of a high specification relational database with the Open Source license. The database engine may be directly accessed via the php scripting language and the Apache webserver to format and present experiment details and results via the standard Web browser interface. The database may also be used to archive source code, scripts and test data. This database software is already used on the staff pages for the Computing Department at Lancaster University, and by other high-profile users, such as NASA. The above Open Source software presents a set of very powerful tools to the researcher. The need to use other software and tools may evolve over time and may be addressed on an as required basis. The fundamental components of the Charging Platform are defined and are ready for integration and use. 4. Example /Experiment Scenario The network shown in Figure 2 represents a simplified Internet network and the charging points of interest that may be used for charging and billing experiments to evaluate charging mechanisms and models. The software and applications running on the servers and end systems in the network may be stored and archived on the Charging Platform and the downloaded to the servers prior to the start of the experiments. The experiments would then be controlled by the Charging Platform according to the test descriptions. 4

5 Metering Tickets Access Network Core Network Metering Tickets Metering Tickets Figure 2 Charging/Accounting Points in a Simplified Internet The test data and programs may be exchanged with the test network servers and end systems using standard network methods and mechanisms, for example ftp, sockets, telnet, rlogin, rmi, http, cgi, etc. These methods and mechanisms may also be used to control and execute the experiments over the network under test. Additional servers and end systems may be added to the network under test as required and then configured and controlled by the Charging Platform. Core Network Charging Platform Metering Tickets & Data Charging Models Database Results Reports Figure 3 Data Processing by the Charging Platform If the Core and s also support programming, i.e. active routers, then suitable software or modules may be archived on the Charging Platform and then distributed or loaded to the active routers prior to the start of the experiment(s). Data from the Core and Edge routers may be collated at the Charging Platform automatically using push or pull techniques and methods as appropriate in the network. The charging data is then entered 5

6 into the database on the Charging Platform and the required data processing may be performed and the results may be presented in Web form or downloaded in text, data or diagram form for use in reports. An example of how the data processing may be implemented in a schematic form on the Charging Platform is shown in Figure 3. The experiments carried out in this way may then be replicated and repeated many times so that accurate measurement of the results may be obtained. Also exact reproducibility of the experiments becomes possible, and so experiments may be performed at varying times of day, week or month, in case of varying network load having an impact on the results. Once example test cases are set up on the Charging Platform they may be used as a template for new test cases. The requirement to make the definition of the test cases and data capture becomes important here to ensure that the Charging Platform becomes a useful tool for researchers and not a burden on development, research and experiment time. The emphasis is to create a useful research tool. 5. Next Steps and Conclusions The first stage is to set up the basic Linux server that will act as the Charging Platform, including the installation of the proposed Open Source software and verify the system to be working as required. Development work on the scripts and the Webpages may then begin, to provide the interface to the Charging Platform. This will include database work to support the network experiments and the Webpage generation. Once the platform is in place the development and implementation of the charging mechanisms and models may be worked on within the structure of the Charging Platform. This should initially be carried out on a simple network configuration with a suitably simplified experiment to prove the concept for more complex configurations and experimentation. With time it hoped that the Charging Platform will provide a stable resource for research in this technical area. The basic concept and tools of the Charging Platform may also be migrated to other areas of research where the assimilation and presentation of data and results is time consuming and problematic for researchers. 6. References [AAA] [Apache] [Cai] [Clark] IRTF AAAarch - Apache Webserver - J. Cai and D.J. Goodman, General Packet Radio Service in GSM, from IEEE Comms Magazine, October 1997 pp D. Clark, A Model for Cost Allocation and Pricing in the Internet, MIT Workshop on Internet Economics, March 1999 (ISBN ) 6

7 [Cost263] COST Action 263, Quality of future Internet Services - [Cushnie] J. Cushnie, D. Hutchison, H. Oliver, Evolution of Charging and Billing models for GSM and Future Mobile Internet Services, published in Proc. QofIS'2000 Symposium Berlin, Germany, September 2000, Springer-Verlag LNCS 1922, (ISBN ), pp [GCAP] Global Communication Architecture and Protocols (GCAP) [IETF] [IPV6] [IRTF] IETF - IPv6 - IRTF - [McKnight] L.W. McKnight, J.P. Bailey (Eds), Internet Economics, MIT Press, April 1997 (ISBN ) [MySQL] [PHP] [RedHat] [Shenker] [UMTS] [WAP] [XML] MySQL - php Hypertext Preprocessor RedHat Linux Distribution - S. Shenker, D. Clark, D. Estrin, S. Herzog, Pricing in Computer Networks: Reshaping the Research Agenda, from ACM Computer Communication Review. 26 (1996) pp UMTS Forum - Wireless Application Protocol - XML - 7