Chapter 2. The Network Application Model

One of the principal tenets of the Zen of Palm is that a solution should anticipate the needs of the majority of its users. The Palm protocol stack certainly meets this criteria—it is TCP/IP-based. TCP/IP is the lingua franca of the Internet; the majority of applications will use TCP/IP or its sibling in the Internet Protocol Suite, UDP/IP.

A network programming interface allows the application to access the protocol stack in a transport and network independent fashion. The Palm OS provides a reasonable subset of the Berkeley Sockets interface, the de facto standard network programming interface. The Net Library's interface has not changed since its introduction four years ago. In this chapter, we introduce the Open System Interconnect (OSI) model, the ISO standard for network protocol stacks, and the Berkeley Sockets API, which is the de facto standard programming interface to network services. We examine how these models have been applied on the Palm OS platform.