26-06-2013, 03:15 PM
Design and Implementation of a Web-based Internet/Intranet Mail Server Management System
Implementation.pdf (Size: 226 KB / Downloads: 98)
Abstract
Electronic mail service is one of the most
essential and well-known Internet/Intranet application
services. Users expect their electronic mail service to be
reliable and efficient, while administrators demand reliable
and efficient tools to satisfy users’ expectations. Mail server
management system is a good solution for such requirements
from different user groups. We have designed and
implemented an SNMP manager and SNMP agent system that
can manage Internet/Intranet mail server systems. The system
has been integrated with WWW technology such as Java and
CGI. The Java-based GUI system enables human users to
manage mail server systems from anywhere with friendly,
easy-to-use Web browser interfaces. The system architecture
is also general enough so that it can be easily extended to
manage any other Internet/Intranet application services.
Introduction
The rapid growth of the Internet and World-Wide Web
(WWW) [1] has allowed more people access to global
computer network and network applications. Internet Service
Providers (ISP) profit by offering many kinds of Internet
services such as electronic mail, WWW, FTP, and others.
Some closed computer user groups such as companies,
research centers, or a universities, have opted for smaller,
Internet-like network environments called ‘Intranets’.
Intranets provide integrated network services using Internet
technologies that are, technically, the same as Internet’s.
Intranet services, however, are more integrated and taskspecific
services with consistent user interfaces. Intranet is
gradually replacing old proprietary messaging systems such
as Bulletin Board Systems (BBS) and document processing
systems.
Electronic mail service is one of the most popular and
essential services in both Internet and Intranet. There could be
no Internet/Intranet services without the electronic mail
service. Mail server is a computer system that sends and
receives electronic messages for a number of users in a
certain management domain. Mail servers are connected to
networks and should reliably process incoming and outgoing
mail messages. Sending and receiving tasks are actually
processed by a special software called mail server program
running in the mail server. The most widely-used Internet
mail server program is sendmail, which was first developed
in 1982 for 4.1 BSD UNIX system [2].
SNMP and Mail Monitoring MIB
Simple Network Management Protocol (SNMP) is a standard
protocol suite for the Internet network management. Internet
Engineering Task Force (IETF) first standardized the protocol
and initiated SNMP-based management. The original targets
for this effort were TCP/IP routers and hosts. However, the
management architecture is inherently generic so that it can
be used to manage various types of systems.
The SNMP network management model consists of the
following elements [8, 9]. SNMP management defines two
network entities, managing system and managed system, and
the communication methods between two entities. Managing
system contains one or more processing elements called
management applications, shortly, managers. Manager
performs management functions over managed nodes it
controls. Each managed system has a processing entity called
an agent which gathers various management information from
the managed system. SNMP itself is a set of communication
methods between manager and agent. The protocol defines
three basic operations, GET, SET, and TRAP. The GET
operation is initiated by a manager for retrieving management
information from an agent. When the manager needs to
change management information in managed systems, the
manager performs the SET operation on the specified agents.
The TRAP operation is an unsolicited communication from
agents to managers. Agents send TRAP information to
specified managers when managed system initiates any events.
System Design
Our Internet/Intranet mail server management system has
three architectural parts: SNMP agent, SNMP manager, and
Java-based management application. SNMP agent is a process
running on the mail server system that is supposed to be
managed by SNMP manager. SNMP agent process keeps
track of management information in the mail server system
and provides the information to the SNMP manager. SNMP
manager is a process running on the managing system that
controls SNMP managed systems by communicating with the
SNMP agent process. Java-based management application is a
Java applet running on the human manager’s Web browser.
Easy-to-use graphical user interfaces are provided by the
applet application. Also, the management information is more
understandable in Web-based management system comparing
to proprietary text-based management systems.
Implementation
In this section, the implementation details of our
Internet/Intranet mail server management system are
presented.
We have chosen Java as the main programming language
of our system modules. Java which is developed by Sun
Microsystems is a simple, object-oriented, interpreted, robust,
secure, architecture neutral, portable, multithreaded, and
dynamic programming language [15]. The language
originally designed for controlling consumer electronics is
now widely used in developing Web-based applications.
SNMP-based communication can be implemented easily
by using Java. Java provides TCP/IP socket interfaces for
such kinds of communication applications. However, there is
much more efficient way of developing SNMP-based
management system in Java. Java class package dedicated to
SNMP communication is freely available from many
organizations.
MTA Manager System
MTA manager system has several roles. It runs Web server
for distributing Java-based management applications to Web
browsers. The Web server is also used for showing static
information pages in HTML. The manager system
communicates with MTA agents via SNMP. It sends SNMP
GET and SET operations to SNMP agent process and waits
for SNMP TRAP messages from SNMP agent process.
Finally, it summarizes and analyzes management information
and reports the information to Java-based management
applications.
Manager process consists of two different threads. SNMP
manager is responsible for handling management operations
from Java-based management applications. SNMP manager
process sends SNMP GET or SET messages to the
appropriate SNMP agent processes according to the
management operations. Operation results or responses are
manipulated by SNMP manager and transferred to Java-based
management applications.
Conclusion
In this paper, we have presented the design and
implementation of a Web-based Internet/Intranet mail server
management system. We have used and integrated SNMP and
Web technologies in developing our system. The SNMP
management framework enables developers to create
management applications easily and efficiently. We have
defined SNMP MIB module for monitoring mail server
process and have designed SNMP manager and agent system
which can handle SNMP MIB information.