Networking architecture is based on the concept of
layers. From Java Network Programming (Harold,
2000.) comes this layer model:
(A more formal OSI - Open System Interconnection -
model has 7 layers but this one shows the essential layer definitions.)
Each layer has its own standardized protocols and
applications programming interface (API ), which refers to the functions,
and their arguments and return values, called by the next higher
Internally, the layers can be implemented in different
ways as long as externally they obey the standard API.
For example, the Network Layer does not know if the
Physical Layer is Ethernet or a wireless system because the device
drivers respond to the function calls the same way.
The Internet refers primarily to the Network
Layer that implements the Internet Protocol (IP) and the Transport
Layer that implements the Transmission Control Protocol (TCP). In
fact, you often here people refer to the "TCP/IP" network
rather than calling it the Internet.
The application layer also includes various protocols,
such as FTP (File Transport Protocol) and HTTP (Hypertext Transfer
Protocol) for the Web, that rely on the TCP/IP layers.
Most users never look below the application layer.
Most application programmers never work below the TCP/IP layers.
References & Web Resources
Basics – Sun Java Tutorial
- E. R. Harold, Java Network
Programming, 2nd Ed., 2000, O’Reilly.
- P. Niemeyer and Jonathan Knudson, Learning
Java, 2nd Ed.,2002, O’Reilly.
- Ian F. Darwin, Java Cookbook, 2nd Edition, O'Reilly, 2004.
Latest update: Dec. 8, 2004