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.
The OSI Model
The International Organization for Standardization (ISO) defines technical and mechanical standards for the industry. ISO is a worldwide federation of national standards organizations from 130 countries. The American National Standards Institute (ANSI) defines these standards in the U.S. and is a member of ISO.
ISO is not an acronym for International Organization for Standards,
or anything else. It is derived from the Greek word
iso, meaning equal.
ISO produces ...