Summary

In this chapter, we saw how ESB provides a concrete infrastructure for SOA,extending the simple services model to include a robust service bus with extensive mediation functionality

ESB extends the omnipresent P2P model of Web Services. We saw how ESB provides the middleware functions for SOA via its communication backbone, mediation services, and its services infrastructure. ESB leverages Web Services standards where possible—though standards are yet to come up in the ESB service runtimes space. Until then there will be limitations in terms of portability of applications from one vendor's ESB platform to another.