WEB SERVICES IN TELECOMMUNICATIONS, PART II
Sean Moore, Ling Liu · 2008
his is Part II of the feature topic “Web Services in Telecommunications”; Part I appeared in the July 2007 issue of IEEE Communications Magazine. In our editorial for Part I, we noted that Web services represent yet another area of convergence between telecommunication and data technologies. The convergence may be characterized primarily as a migration of telecommunications toward the data world in which telecommunications adopts and adapts TCP/IP and XML protocol suites, as well as Web technologies in general, to meet its requirements. During the eight months between Parts I and II publication, we have observed that the convergence and migration have continued at a rapid pace, and have now reached the point where one may assume that many emerging telephony technologies and applications are architected as Web technologies and applications. Within the Web technology space, Web services continues to be the preferred environment for machine-to-machine interoperation, with obstacles and resistance to its adoption being removed and new uses for Web services being identified, some of which are presented here. We partitioned the articles into strategically themed articles (Part I) and tactically themed practical articles (Part II) with the intent that such a partitioning would align with processes and timelines of any RD the article by Griffin and Pesch in Part I functions in this role for Part II. One potential obstacle to adoption of Web services for telecommunications messaging is performance. Web services messaging is built on the XML-based SOAP framework, which provides flexibility and interoperability but at the cost of performance when compared to traditional protocols. The articles by Mulkey and Saiedian, and Zilora and Ketha directly examine the performance of Web services in telecommunications contexts. Mulkey and Saiedian take an architectural approach to performance optimization of Web services when used as the eventing protocol for event-driven “soft” real-time systems, a category in which many telecommunications and telephony systems belong. The performance factors considered include the transport protocol, data model (which grows in size as a function of the model’s complexity), and processing resources (e.g., for XML parsing). Among the conclusions derived from the analysis of their experiments is that Web services processing should be located at the network edge rather than in the core, a result that may impact, for example, application-aware network design and the location of SOAP intermediaries. Instead of an architectural approach, Zilura and Ketha take a direct engineering approach to performance evaluation and present a methodology for optimizing Web services performance in a telecommunications environment. The methodology shows how to test the performance of servers hosting Web