Figure 1 network management architecture[2]
Peng Gao&Rui Zhao
Electronic and Telecommunication
Helsinki University of technology
Penggao@cc.hut.fi
1 Introduction
1.1
What is network management
1.2
Main fields of the network management
1.3 Requirement of network management
2 Network
management architecture
3
Main protocols used in network management
3.1 SNMP
3.2 CMIP
4
New technology used in network management
5 Conclusion
References
Further information
Configuration management is perhaps the most important part of the network management because without the ability to manage the configuration of the network we can not realize the real network management. The goal of configuration management is to monitor network and system configuration information so that the effects on network operation of various versions of hardware and software elements can be tracked and managed. All network software and hardware configuration information should be store in a database which allow the dynamic updating and ease access.[2]
Accounting management help us to measure network-utilization
parameters so that individual or group uses on the network can be regulated
appropriately.
Performance management is to measure and make available
various aspects of network performance to maintain the performance of network
at a acceptable level. In the field of network management, there are no
functional address of systems or applications performance management.[7]
The main field of Security management is to monitor and
control the access to network resources according to local guidelines so
that sensitive network resources can only be accessed by right users. Most
network management application only address security applicable to network
hardware but not really deal with system security. [2,7]
First network management should has the most efficient utilization of the bandwidth of the network. The propose of using network management system is to protect the most availability of the network and we can not suffer much band utilization of the management system which has bad influence to the application systems on the computer network. Second, network management would have to be extensible. The network architecture was being designed to allow the use of multiple modules that would provide the same or similar services at each layer and to simultaneously support multiple-layer protocols in a network. Therefore, the management architecture transparently assimilate new devices and technologies. The network management architecture had to become as extensible as the network architecture. Finally, since network layer was designed to be an open architecture, management of network layer components would have to be effective in a multivendor network. Our design had to ensure that the ability to provide effective management of network components was independent of the vendors supplying them.
Managed devices can send alerts when some problems happen.
Then management entities react to those by executing one or a group of
actions such as event logging or system shutdown which have been programmed
previously. However management entities also can poll end stations to check
the values of certain variables automatically or user-initiated. The agents
in the management devices will respond to all that polls, that are software
modules compiling information about the corresponding to the managed devices.
After that agents will store those information in a management database
and then report it to management entities within network management systems
through some network management protocol(SNMP). In addition, there are
management proxies that can provide management information on behalf of
other entities.[6]
Figure 1 network management architecture[2]
A SNMP managed network consists of three main components:
managed devices, agents, and network-management server. A managed device
is a network node within a managed network with a SNMP agent in it. Agent
is a kind of program module resides on the managed devices which have the
function gathering the management information, translating information
into a form compatible with SNMP. Server executes applications to monitor
and control managed devices through the agents.[3]
Figure 2
components of the SNMP network[ 3]
One main technology used by SNMP is Management
Information Base(MIB) which is a collection of information organized hierarchically.
MIBs are comprised of managed objects and are identified by object identifiers.
Managed object is one of any number of specific characteristics of
a managed device and is comprised of one or more object instances. Object
identifier (or object ID) uniquely identifies a managed object in the MIB
hierarchy. The MIB hierarchy can be depicted as a tree with a nameless
root, the levels of which are assigned by different organizations.[8]
The way SNMP works is simple: It exchange the network
information gotten by SNMP entities through messages known as protocol
data units(or PDUs). There are five types of PDU's in the first version
of SNMP to monitor a network by which prescribed by Abstract Syntax Notation
One(ASN.1): two deal with reading terminal data(Get and GetNext PDU's),
two deal with setting terminal data(Response and Set PDU's), and one(trap
PDU's) is used for monitoring network events such as terminal start-ups
or shut-downs. There are two kinds of working methods by using these five
PDU's. First is the server use Get or GetNext PDU's to ask the agents on
the management devices using Response PDU's to report the information of
management devices, and then according this information server use Set
PDU's to control the agent to do some thing. Second is agents on the management
devices report the information of managed node by using Trap PDU's automatically
when the state of managed device changes and server send some Set PDU's
to related agent according to this trap.[1,3]
There are four main advantages using SNMP as the
fundamental protocol of network management:
But unfortunately CMIP need ten times network resources
than SNMP need and can not be applied by any systems on this planet. And
because of its complex and sophisticated data structures it is very difficult
to program and has a bad expandability. So till now there are very little
system using CMIP as its network management protocol.
Perhaps the most powerful advance to be deployed for WBM is the Java language. Java is an interpretive programming language, meaning that code is "interpreted" at run time by a processor-specific program (i.e., interpreter), rather than compiled prior to running. Interpretive languages are portable across processors to the extent that interpreters are written for specific processors. With Java, the interpreter is a powerful device called the Java Virtual Machine (JVM). JVMs are available for a wide variety of different processor environments and, more critically, are bundled into Web browsers such as Netscape Navigator and Microsoft Internet Explorer, enabling these Web browsers to execute Java code.[5]
Java can be employed to create stand-alone applications that run on workstations, in the same way as C++ and other languages are used. But Java does have built-in Web-enabled capabilities. Most significantly, self-contained Java programs, called applets, can be sent to a browser and run locally on the browser’s machine. Technically, applets and applications differ in that applets have browser-imposed security constraints, which stop applet access to local system resources—such as memory and disk—and limit access to network resources. Applets, therefore, can be securely passed and executed with minimal risk to the receiving machine and without breaching network security.[5]
Java applets are a powerful technique for managing and
presenting dynamic data needed for advanced WBM. Unlike HTML, Java can
be used for such tasks as displaying dynamic graphs of network activity
or painting complex pictures, such as an interactive view of a chassis
hub or modules of a stackable hub. Java applets can present real-time information
displaying graphs or adding animation, are low risk. However, long-term,
as Java becomes embedded and takes on broader tasks, Java code integrity
will need to be protected. To address this, there are emerging technologies
to add encryption and "electronic signatures" to applets. These techniques
will ensure that received applets are identical to the original, thus protecting
users from the effects of applet tampering and corruption.[5]
http://www.inforamp.net/~kjvallil/t/snmp.html
<2> Cisco System Inc. / Network Management Basic, Jun 17th 1999 [referred Oct 30th 1999]
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/nmbasics.htm
<3> Cisco System Inc. / Simple Network Management Protocol(SNMP), Jun 17th 1999 [referred Oct 31th 1999]
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/snmp.htm
<4> Hyde D. Web-Based Management, Mar 1997[referred Nov 01th 1999]
http://www.3com.com/nsc/500627.html
<5> Lawton G. / Java brings mew opportunity to network management, Dec 1996 [referred Nov 01th 1999]
http://www.javaworld.com/javaworld/jw-12-1996/jw-12-manage.html
<6> Pras A. / Network Management Architectures, 1995 [referred Oct 28th 1999]
http://alpha01.ihep.ac.cn/~caixj/netm/nm/general/NM_architecture.pdf
<7> Stevenson D.W. / Network management, April 1995 [referred Oct 29th 1999]
http://netman.cit.buffalo.edu/Doc/DStevenson/
<8> Wong E. / Network Monitoring Fundamentals and Standards, Aug 14th 1997 [referred Oct 29th 1999]
http://www.cis.ohio-state.edu/~jain/cis788-97/net_monitoring/index.htm
Introduction
to version 2 of theInternet-standard Network Management Framework
The concise description of the SNMPv2
Remote
Network Monitoring Management Information Base
This document treats the special subject
about remote network monitoring MIB.
Report
of the Second Ad Hoc Network Management Review Group
Analyses some elements of Internet
management and brings some problems, possible solutions and development
direction of network management.
The
Pocket Network Management Survival Guide
Demystify some of the most commonly
encountered network management terms and concepts.
The
business value of network management
This article values the network management
for the business use.
What
is network management
Give some answer of the question What
is network management.