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Unit 12: Secure Application




          protocol (WSP) layer offers a lightweight session layer to  permit efficient  exchange of  data  Notes
          across applications.




              Task  What does denial of service protection mean? How is it accomplished in the WAP
             architecture?

          12.2.2 Comparison between WAP and Internet Protocol Layers


          WAP architecture offers scalable and extensible environment for application development for
          mobile communication devices. This is achieved through the layered design of the entire protocol
          stack. Each of the layers of the architecture is accessible by the layers above, as well as by other
          services and applications.
          A pictorial comparison between WAP and the Internet Protocol Layers is given in Figure 12.6.


                                            Figure  12.6
                 WAP Protocol Layers
                                                       Internet Protocol Layer
                 Browser/Application:WAE
                                                       Browser or Application

                         Session:WSP
                                                       Session/Transaction: HTTP


                        Transaction:WTP
                                                             Security:SSL/TLS

                         Security:WTLS
                                                            Transport: UDP/TCP

                     Datagram Transport WDP
                                                                 Media

                           Bearers




          The WAP layered architecture enables other services and applications to utilize the features of
          the WAP stack through a set of well-defined interfaces. External applications may access the
          session, transaction, and security and transport layers directly. The following sections provide
          a description of the various elements of the protocol stack architecture. These layered applications
          are symmetric; they reside both on the client device and the WAP Gateway. This layered structure
          is very similar to the Internet Protocol Stack.
          Bearers


          The WAP protocols are modeled to operate over a variety of bearer services, including short
          message, circuit-switching data and packet data. The bearers offer differing levels of quality of



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