A client and a server communicating through a PPS server object can use whatever messaging format is required.
In principle any PPS attributes can be sent to a server object. However, to aid interoperability between clients and servers, we recommend the protocol described in the following sections.
This protocol defines how messages are sent from one side to the other and how replies to messages are identified. The protocol is symmetric; the method used to send messages is independent of whether an application is a client or server.