HyperText Transfer Protocol (HTTP), along with its secure cousin, HTTPS, is the most widely used application-level protocol for transporting remote invocation messages between a Web services client and the Web service provider, typically a Web server or JSE. As such, HTTP/S is the modern telephone line for the communications portion of Web services. It is ubiquitous and meets the basic requirements fulfilled by the telephone line, handling secure communications between Web service clients and providers located anywhere in the world.

Thus, most Web service clients can exchange messages with Web services using a standard HTTP/S Post method and Response. Again, because it is already widely used for secure and nonsecure Internet data communications in a connectionless mode, it is already the prevailing Web services standard, avoiding the need to create a new Web services communications protocol or the client/server technology to support it.