TCP/IP Tutorial and Technical Overview - IBM Redbooks

18.6.3 Push access control protocol (PAP)
The push initiator uses PAP to push content through a PPG to the WAP domain.
PAP is carried over an HTTP 1.1 tunnel. PAP carries an XML-style entity.
PAP operations
PAP supports the following operations:
► Push submission (initiator to PPG)
The push message contains a control entity, which provides delivery
instructions for the PPG, a content entity, which is the textual content for the
WAP terminal, and, optionally, a capability entity.
Depending on the message type (WML or WMLScript), PPP converts this
message into a more bandwidth-optimized form before forwarding
over-the-air (OTA). Also, encryption can be used when sending the message
to the client.
► Result notification (PPG to initiator)
If the push initiator has requested confirmation of successful delivery, a
notification message is returned to the push initiator. This gives the push
initiator the awareness that the WAP client has also acknowledged the
successful delivery to the PPG.
► Push cancellation (initiator to PPG)
This XML-entity is sent from the push initiator to the PPG, requesting that a
previously submitted content be cancelled. The PPG responds if the
cancellation was successful or not.
► Status query (initiator to PPG)
The push initiator requests the status of delivery during the 2-way process to
the WAP client:
– First way: Push initiator → PPG
– Second way: PPG → client
► Client capabilities query (initiator to PPG)
The push initiator requests, from the PPG, information about the capabilities
of a particular WAP terminal. The PPG responds with a multipart/related
message in two parts:
– The first part is about the execution of the message itself.
– In the second part, the capabilities of the WAP terminal defined by the
User Agent Profiles group is reported.
Chapter 18. Wireless Application Protocol 667