NETWORK MANAGEMENT BASED ON PC COMMUNICATION
PLATFORM WITH SNMP AND MOBILE AGENTS
Jae-Kyu Chun ,Ki-Yong Cho, Seok-Hyung Cho, Young-Woo Lee, Young-Il Kim
Access Network Lab., R&D Group, Korea Telecom, Korea
E-mail: { jkchun, kycho, shjo, ywlee, yikim}@kt.co.kr
Abstract
We have constructed Information Communication
Processing System(ICPS) and Advanced ICPS(AICPS) as
a kind of gateway system using communication service
network to provide PC communication service(on-line
dial-up service) to users (customers). Users could connect
ICPS or AICPS using 01410/01411/01412 connection
dial number, especially management of 01412 PC
communication service network resource provides
resource data through one Local O&M System(LOMS)
per each AICPS. Nation-wide integrated network
management has been provided centralized integration
operating network management service through
POWWOW-NMS which manages Network Elements(NEs)
in PC communication network. We implemented network
management system(NMS) of POWWOW-NMS in PC
communication network. We also analyze SNMP pollingbased network management in comparison with agentbased network management.
1. Introduction
Korea becomes the one with rapid growth in the
Internet community and related business. Internet access
through super-high speed network has also exponentially
increased about 4.5 million today. It catches the
international attention as a unique and viable business
model of Internet community.
The motivation of ICPS/AICPS’s development is as
follows; ICPS/AICPS provide services using PSTN, ISDN
with multiple network connection to users, even though
Remote Access System(RAS) provides connection
between PSTN, ISDN and Internet network. ICPS/AICPS
provide connection service of packet network, frame
network as well as internet, including Menu Manager
service, Inforshop/ Web-Inforshop service and so on.
Network management is a critical issue in today’s
rapidly changing network environment. POWWOW-NMS
effectively operates and manages network traffic and
network resources on PC communication network based
on
ICPS/AICPS.
POWWOW-NMS
has
been
implemented that it collects, stores and manipulates
necessary Operation & Management(O&M) data for
configuration
management,
fault
management,
performance management, keeping pace with phased
development of ICPS/AICPS since 1995.
This paper is organized as follows; The first section
provides a brief overview of the trends of PC
communication service, especially dial-up service. The
section following that briefly outlines the development of
ICPS/AICPS and describes Network Management
System(NMS) of POWWOW-NMS and Service
Management System(SMS), A-GAUSS, providing PC
communication network service and also provide
POWWOW-NMS’s architecture and operating user
interfaces. This paper goes on to compare with traditional
network management method and mobile agent model
applied to POWWOW-NMS. Last section concludes the
paper with future works.
2. Phased PC communication network
development
The system have been developed to provide PC
communication service using 01410/01411/01412 dial-up
connection number. We have provided PC communication
service through three level’s system upgrade.
As the first step, ICPS has been developed and operated
with connecting 01410/01411 dial-number in 1995. ICPS
consists of Information Service Access Point(ISAP),
Mediation Operations, Administration and Maintenance
system(MOAM), Central Operations, Administration and
Maintenance system (COAM) and Guidance And User
management Service System(GAUSS) [1].
As the second step, AICPS had been developed with
substantial functions in comparing to ICPS connecting
01412 dial-number. AICPS consists of Network Access
Sub-system
(xNASs),
High
Speed
Switching
Fabric(HSSF), O&M NAS(ONAS), Local O&M
System(LOMS) and Advanced GAUSS(A-GAUSS). It
totally provides about 80,000 channels.
As the final step, AICPS20 had been developed with
powerful functions such as increasing integration of
xNASs and optimizing system. It totally provides about
110,000 channels. Their general function and
specification can be described as follows:
xNASs also provides connection interface as the same
as AICPS, comprising Telephony NAS(TNAS), PSDN
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Element Management layer(EML) which abstracts all
functions provided with NEL and manages each
network element can be mapped into MOAM, LOMS
and LOMS20. They play a role as managers and ISAP,
xNAS are involved with agents. One MOAM
manages about 20 ISAPs, one LOMS & LOMS20
manage each one AICPS & AICPS20. Data collection
of MOAM, LOMS and LOMS20 performs using
socket.
Network Management Layer(NEL) is that it can
manage the whole networks and system such as
network
configuration,
performance
analysis,
statistics/report. As the same as EML, COAM and
POWWOW-NMS play a part as manager to MOAM,
LOMS and LOMS20 as agents. A COAM manages 17
MOAMs, POWWOW-NMS manages 54 LOMSs and
30 LOMS20s and collects data based on MIB value
using SNMP. At the same time, POWWOW-NMS
uses FTP for traffic analysis data daily.
Service Management Layer(SML) manages the
services offered to customers. GAUSS and A-GAUSS
manage service information such as menu pages
window, Information Provider(IP) information and
Content Provider(CP) item information for routing
INFORSHOP service.
Business Management layer(BML) manages the
overall business. However it does not support on PC
communication network environment.
NAS(PNAS), Frame Relay NAS(FNAS) and Web
NAS(WNAS) not including ISDN NAS(INAS).
ESAS(Ethernet Switch Access Sub-system) provides
32ports with 10/100Mbps Ethernet. It offers switch
function between TNAS and other xNASs.
LOMS20 is implemented on java machine. It supports
web service interface, including AICPS’s ONAS
functions.
A-GAUSS additionally provides graphics menu
management functions as well as text menu services
including editing, creating, downloading and verifying
menu items.
3. TMN based on hierarchical model
Telecommunications Management Network (TMN) is
a framework for the management of the networks and the
services providing an environment for interfacing a
telecommunication network. We are developing
techniques based on TMN concepts that enable efficient
maintenance and operation of a variety of PC
communication systems[2][3][4]. Figure 1 shows the
TMN based manager/agent model between network
element. The architecture of O&M Model for
POWWOW-NMS is as follows;
Network Element Layer(NEL) which is comprised of
network element could be compared to ISAPs, xNAS
of PC communication network. This provides network
management data to upper layer.
• Modeling
- Manager : COAM, POWWOW-NMS
- Agent : LOMS,MOAM
DCN - KTIS : TCP/IP
Protocol : SNMP,FTP
BML
GAUSS
A-GAUSS
POWWOW-NMS-toLOMS/LOMS20
Centralized OA&M for
01412 Network
COAM-to-MOAM
Centralized OA&M
for 01410/01411 Network
SML
COAM POWWOWNMS
NML
LOMS/LOMS20-to-xNASs
MOAM-to-ISAPs
Localized Service and
OA&M Management
EML
MOAM
MOAM
LOMS
MOAM
LOMS
LOMS
LOMS20
LOMS20 LOMS20
40ISAPs/1MOAM
CMIP
SNMP DCOM
CORBA JAVA
ISAP
ISAP
ISAP
ISAP
ISAP
ISAP
ISAP
NEL
PNAS
TNAS
FNAS
HSSF
INAS
ONAS
WNAS
Figure 1. TMN based on hierarchical model
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Localized Service and
OA&M Management
1xNASs/1LOMS
PNAS
TNAS
FNAS
CNAS
WNAS
Service Logic
Application
Confi.
Service
Fault
Service
Perfor.
Service
Message
Service
Download
Service
Fault
Service
Report
Service
CORBA
Radius
Setting
NE Access Logic
Data Access
Logic
Application
Radius
Setter
1.X Service
Data
Operator
Message
2.0 Service
Data
Alarm Event
Service Data Service Data
1X Mediator 20 Mediator
OpMesg
Sender
Event
Provider
Polling Manager
Polling Data
Mediation
DB
Polling
control
Event Count
Collector
Trap
Monitor
FTP
Trap
Database
Access
Polled Data
Poller
Alarm Counter
Management
Polled Data Processing Logic
SNMP
LOMS SNMP Agent/FTP Server
Figure 2. POWWOW-NMS
4. POWWOW-NMS ARCHITECTURE
POWWOW-NMS is separated into three tiers such as
user interface logic application with private client, web
interface program for public POWWOW-NMS or traffic
monitoring and
service logic application providing
network management application functions and data
access logic application collecting network management
data based on communicating between POWWOW-NMS
and LOMS. It is multi-tire architecture connected to
CORBA platform like Figure 2. Functions at each layer
are as follows;
4.1 Functions
User Interface Logic Application : User interface with
circumstances based on windows provides operators
with interface environment services. It is also to
provide that operators execute operation management
of all LOMS and xNASs. Through cooperation of
service application and data access application, user
interfaces efficiently represent infrastructure network
management functions. The kind of user interface is
private POWWOW-NMS, web interface, report
generator etc..
Service Logic Application : Service logic application
interacts with user interface program and data access
application,
with
result
of
each
service
xNAS Conf. Table
xNAS Event Table
AlarmTable
Statistics/Report Table
Temp Table
Architecture
Table backup File
request/response. This layer is possible to execute
stable service requests and flexible network
management system. This layer provides 7 services
such as configuration service, fault message service,
performance service and so on.
Data Access Logic Application : Data access logic
application servers collect data of fault management,
configuration management and
performance
management necessary to PC Communication network
operation management. It is composed of NE Access
Logic and Polled Data Processing Logic. NE access
Logic function consists of pollers, which collect and
transfer management data and polling manager which
optimizes the number of poller to effectively manage
system. Polled Data Processing Logic is located
between database and NE Access Logic, analyzing
data of collecting from poller, reprocessing collection
data as well as event process to provide service request
from service applications.
4.2 Management Services Provided with POWWOWNMS
POWWOW-NMS takes advantage of object-oriented
software features to archive a simple and readily
extensible structure with C++ & Java classes collaborating
to perform a particular function such as FCAPS(FM, CM,
AM, PM, SM). Private MIB is used to communicate
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between powwow-NMS and LOMS, the number of OID
value is about 800. In order to implement management
services,
POWWOW-NMS
provides
standard
management functions such as;
Fault Management : conducting alarm surveillance and
fault correction, modifying alarm notification
conditions, providing alarm reporting, assigning alarm
event criteria functions, managing logs and so on.
Configuration management : setting xNAS/LOMS,
retrieving configuration data, managing database,
installing LOMS, receiving notification of trap for
configuration change and so on.
Accounting Management : creating, deleting,
activating items and so on.
Performance Management : monitoring performance,
controlling performance management, modifying
notification conditions, analyzing performance,
managing logs and so on.
Security Management : authenticating, auditing trails,
managing access logs and so on.
4.3 Method of Effectively Managing Data Collection
We have designed and implemented POWWOW-NMS
in PC communication network to support network
management. However, it has been too much time to
manage and collect 84 NE resources. So, we suggest
several mobile agent method and implement in next
chapter.
5. Mobile agent model
To efficiently manage and operate network resources
the majority of network management model has been
managed by centralized client/server model based on
manager and agent architecture. Centralized client/server
model consists of managing entity, which plays part of
manager, managed Objects and Network management
protocol, SNMP(Simple Network Management Protocol)
of IETF for data networks
and CMIP (Common
Management Information Protocol) of OSI for
telecommunication networks. It is used to exchange
messages in reference to MIB(Management Information
Base), which is hierarchical base of information managed
by each objects.
Mobile agent model reduces the complexity of network
management at the managing entity by delegating
executable code and data to the managed entity. Providing
mobility to an agent in the network management domain is
an efficient way to address some of the critical network
management problem such as network managed entitles’
scalability, service dynamic extensionability and network
overhead etc.. Mobile agents are autonomous,
asynchronous, and optionally intelligent software entities
which in order to fulfill their tasks, can migrate to and
reside in a number of networked nodes [5][6][7][8].
In this paper, in addition to implementing SNMP based
POWWOW-NMS in PC communication network, we
suggest that we cluster NEs and generate mobile agents
simultaneously. In case of many managed NEs, we
suggest that it would be possible to manage efficiently
applying to clustered mobile agent model rather than
snmp based model to provide fault and configuration
information in real time to user.
5.1 Performance Measurement by Using Mobile Agents
Traditional SNMP-based polling, which is intrinsically
centralized, involves a flood of request/response messages.
This naturally leads to a significant proportion of
available bandwidth being used for management data.
On the other hand, mobile agent model generates a
single mobile agent responsible for obtaining network
management data from each managed entity. In addition,
the order in which managed entities are visited is arbitrary.
Peer to peer mode suggests that the number of mobile
agent is required per managed entities. Roaming mode
suggests that a single mobile agent, which is generated at
the network management system, roams distributed
managed entities for collecting management data. As
another approach, the clustering mode suggests that it is to
partition the managed entities into logical or physical
domains.
In this paper, we compare and analyze using four
methods based on POWWOW-NMS environment as
follows. Figure 3 shows parameters for calculating
response time. Figure 4 represents network management
method using mobile agents and numerical formula.
Processing time of NMS - Processing time of agents - β
Processing time of SNMP protocol - r
Network delay among agent nodes - t
The number of agent nodes - n
The number
cluster
among agent
nodes - p
Figure 3.ofTime
consumption
parameters
Peer to peer(1:1) Method : Mobile agents launch from
NMS to each other NE(Network Element) and returns
the results to NMS.
Roaming Method : A mobile agent launches from
NMS to the first NE, with results a mobile agent
moves to the second NE. After all NEs execute, final
results return to NMS.
Clustering Method : After clustering each NEs, mobile
agents move to each clustered group simultaneously.
The partitioning criteria in POWWOW-NMS is
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specified by 10 physical distributions of managed
entities such as Seoul, Pusan, Chunnam etc..
1 :1 Method
SNMP Method : Polling method based on traditional
client/server network management.
Roaming Method
wv~~v~Tutz
wv~~v~Tutz
svtz
svtz
Clustering Method
wv~~v~Tutz
svtz
Figure 4. Network management method using mobile agents
The overall response time could be approximately by T
= ta + tb + tc , where ta represents the network
transmission time of managed data, tb
describes
processing time of network management system such as
processing transmitted data with result of interacting with
managed entities and tc represents the time spent by
agents or managed entities
such as launching or
destroying mobile agents, processing the requests of NMS
in the managed entities[6]. If we represents network
management elapsed(response) time by numerical formula,
SNMP method shows 2nt + n + r. Network transmission
time between NEs and POWWOW-NMS is double,
sending and receiving time. The processing time of
POWWOW-NMS is that the number of receiving of data
from NEs.
Peer to peer method is similar to SNMP based polling
except the time of processing agents. Roaming method
shows that one agent circulates NEs with n+1 (plus
POWWOW-NMS) and the processing time of
POWWOW-NMS is just single time because
POWWOW-NMS processes one agent. Clustering method
represents network transmission time of clustered NEs as
(n+1)t/p because POWWOW-NMS simultaneously
processes mobile agents. POWWOW-NMS’s processing
time is p , sum of processing time with each mobile
agent.
5.2 Comparison of response time
To implement mobile agents, we applied to
POWWOW-NMS operating on PC communication
network(1 POWWOW-NMS + 84 NEs(LOMS) – UNIX
machine). To implement mobile agent system, script
language is widely used. Showing up java language, java
makes an excellent environment by offering a portable,
distributed, heterogeneous and secure function. So, we
selected Java as a test implementation environment
because it supports almost all of the required properties.
To implement mobile agent, we used Grasshopper1.2
library of IKV++ GmbH[9]. This is a kind of
experimental mobile agent systems. Grasshopper is an
agent platform that is entirely implemented in Java,
running on platforms supporting JDK1.2. To efficiently
implement mobile agents, we partly get private
OID(Object Identity) values of 50 in POWWOW-NMS’s
1000 polling values.
Figure 5 graph shows a comparative analysis of their
performance. By using mobile agents, especially
clustering method, we could get 20-30% performance
improvement rather than SNMP based polling. We
determined the performance of SNMP polling and mobile
agents by measuring the response time, the time between
the launch and the return of a mobile agent from NMS.
The response time depends on several factors, such as
CPU speed each time and network environment. However,
we pay no attention to these factors. By trying to test 20
times, we get average response time. The overall response
time consists of network transmission time, NMS
processing time and agents’ processing time.
The response time has results similar with SNMP
method and Peer to peer mobile agent method. As
network entities increase, the overall response time
drastically increases by using SNMP polling method by
which network traffic and processing time have been
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ůũ
űŭ
Ů
ūũ
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caused. However, if managed entities are minor, SNMP
polling method is better than any other methods.
The performance results in a significant improvement
in response time by increasing managed entities. As a
result, even though most mobile agent based
infrastructures exhibit scalability limitations when data
intensive management applications are considered, the
performance using mobile agent surpass SNMP-based
polling performance because mobile agents gather
distributed data at a once.
MNAS(Mobile Network Access Subsystem)
provides wireless, wireline integrated services.
which
7. References
[1] Young-il Kim, “An Implementation of Centralized
O&M System for CPS Network”, APNOMS,
September 1998.
[2] Dittrich, A, Hoft M., “Integration of a TMN-based
management platform into a CORBA-based
environment”, Network Operations and Management
Symposium, 1996., IEEE , 1996.
[3] Agoulmine, N.; De Souza, J.N., “A general
implementation architecture for TMN systems”,
GLOBECOM '94. Communications: The Global
Bridge., IEEE , 1994.
[4] Lakshmi Raman, “OSI Systems and Network
Management”, IEEE Communications Magazine,
Volume: 36 Issue: 3, March 1998.
Figure 5. Comparison of response time
6. Conclusion
This paper introduced trends of PC communication
service and in order to support PC dial-up service,
referred to how ICPS/AIPCS had been processed and
developed. We presented the design and implementation
of powwow-NMS for PC communication network
management. We also had experimental test and evaluated
mobile agent model in POWWOW-NMS.
Mobile agents will have a great potential to influence
the design of future network managements, since they
represent an alternative to the traditional client/server
model.
However, agent technology will probably not replace
traditional client/server computing environment entirely
rather than just regarding “add on” existing platform.
Distributed network management is becoming essential
due to the growing trend in internetworking and the
complexity of network entities. Even though dial-up
service’s usage decreases, network management is
important to be effectively used in deployed network
resources and to be continuously improved in the area of
performance, flexibility, scalability and reliability today.
In order to use existing ICPS/AICPS system, the
research is going on additional functions such as
VOIP(Voice over IP) which allows voice information to
be transported over the packet network, CNAS(Common
Channel Signaling No.7 Network Access Subsystem)
which supports No.7 signal instead of R2 signal and
[5] Danny B. Lange and Mitsuru Oshima, “Seven Good
Reasons for Mobile Agents”, Communications of the
ACM, March 1999.
[6] Hosoon Ku, et al., “An Intelligent Mobile Agent
Framework for Distributed Network Management”,
Globecom ’97 Phoenix, AZ. Nov3-8, 1997.
[7] Markus Breugst, “On the Usage of Standard Mobile
Agent Platforms in Telecommunication
Environments”, IS&N, May 1998.
[8] Markus Breugst, Thomas Magedanz, “Mobile AgentsEnabling Technology for Active Intelligent Network
Implementation”, IEEE, May 1998.
[9]IKV++ GmbH, “Grasshopper : A Platform for Mobile
Software Agents”, 1999.
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