NetWork management

seven layer OSI model

physical layer: The physical layer defines all electrical and physical specifications for devices.

Data Link Layer: The Data link layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the Physical layer.

Network Layer: The Network layer provides the functional and procedureal means og tranafering varible length data sequences froma source to a destination via one or more networks while maintaining the qulity of service requested by the Transport layer.

Transport layer: The purpose of the Transport layer is to provide transparent transfer of data between end users, thus relieving the upper layers from any concert with providing reliable and cost-effictive data transfer.

Session layer: The Session layer provides the mechanism for managing the dialogue between end-user application processes.

Presentation layer: The presentation layer relieves tha spplication layer og concern regarding syntactical differences in data representation within the end-user systems.

Application layer: the higest layer, this lyer interfaces directly to and performs common application services for the application processes.

What are Web Services

A web services is a piece of business logic, located somewhere on the Interenet, that is accessible through standard-based Internat protocols such as HTTP, or SMTP.
XML based and SRPC....
Major Web Services Tech: SOAP, WSDL, UDDI

WSDL ---CORBA IDL

What is J2ME?

J2ME providers a complete set of solutions for creating state-of-the-art networked applications for small devices.
Hight-Level View:
1.A series of JVMs, each for use on different types of small devices,each with different requirements
2. A group of libraries and APIs that can be run under each of the VMs,theses are known as configurations and profiles.
3. Various tools for deployment and device configration.


Configurations: Connnected Limited Device Configuration and Connected Device Configuration
Virtual Machines: KVM and CVM
Profiles:MIDP, PDA,Foundation,RMI and Personal

HOST OS ->KVM ->CLDC ->MIDP and PDA
HOST OS ->CVM ->CDC ->Foundation -> RMI and Personal

WO Install

1. jdk, 1.3 c:\ but in the envr sometime set jdk13~1.1_0 (strange)
2. install jai in two places jdk and JavaSoft jre
3.install framework, application
4. don't forget the port in configration file.
5If IP or name changed, don't forget the DNS setup, Apache