차세대 인터넷 망관리 기술차세대 인터넷 망관리 기술

2000. 12. 12이 재 용

연세대학교 전기전자공학과jyl@nasla.yonsei.ac.kr

차세대 인터넷차세대 인터넷

TCP/IP 기반의유선 Web 응용 서비스

~2002 ~2005

개 인 : ADSL (1.544Mbps)사무실 : 고속 LAN (10Mbps)

무선 인터넷

무선 모뎀 (64Kbps)IMT-2000 (128K ~ 2Mbps)

QoS 제공 기반의Web 응용 서비스(Intserv/Diffserv)

유 · 무선 고속 통합 인터넷

All-IP 무선 인터넷

개 인 : 6Mbps사무실 : 10Mbps

Traditional SNMP ManagementTraditional SNMP Management

DeviceDevice

AgentAgent

DeviceDevice

AgentAgent

DeviceDevice

AgentAgent

NMSNMSDBServer

DBServer

For Long-term Analysis

Periodic pollingUsing SNMP

FunctionsFunctions

Basic Functions Admin framework

handling MIB browser

Applications Fault mgmt Configuration mgmt Accounting mgmt Performance mgmt Security mgmt

Other functions DB interface

차세대 인터넷 망 관리 요구사항차세대 인터넷 망 관리 요구사항

통합 망으로 인한관리 망 크기의 증대

새로운 서비스 출현으로인한 서비스 관리

End-to-End QoS보장 관리

확장성(Scalability)

유연성(Flexibility)

강인성(Robustness)

End-to-endScope고속화에 따른

관리

분산 관리Paradigm 의

필요성

- 구조

- 관리 객체

•관리 통신•Agent•Master

분산 망 관리 동향 분산 망 관리 동향 (1)(1)

구조적 측면 OSF (Open Software Foundation)

DME(Distributed Management Environment) IETF (Internet Engineering Task Force)

AgentX (Agent Extensibility Protocol) ITU/TMN

ODMA (Open Distributed Management Architecture) FIPA (Foundation for Intelligent Physical Agents)/OMG

Mobile Agent

분산 망 관리 동향 분산 망 관리 동향 (2)(2)

관리 객체 측면 OMG

CORBA (Common Object Request Broker Architecture) SUN etc.

Java RMI(Remote Method Invocation) JMX(Java Management eXtension)

IETF RMON I, RMON II Functional MIB (Expression MIB, Event MIB, Scheduling MIB)

ITU Event Notification / M-Action

WBEM ArchitectureWBEM Architecture

Common Common Information Information Model (CIM)Model (CIM)

SNMPSNMP ObjectsObjects

CMIPCMIP ObjectsObjects

DMIDMI ObjectsObjects

ManagedManaged ObjectsObjects

Win 32Win 32 ObjectsObjects

Object ProvidersObject ProvidersSNMPSNMPCMIPCMIP RPCRPCXMLXML Win32Win32

CIM Object ManagerCIM Object Manager

COMCOM

ManagedManagedNodeNode

DCOM / XMLDCOM / XML

OtherOtherManagement AppManagement App

DCOM / XMLDCOM / XML

WindowsWindowsManagement AppManagement App

BMC software 구조BMC software 구조

CORBA-based Inter-domain Manager CORBA-based Inter-domain Manager Using WebUsing Web

CORBA – based Inter-domain Manager

CORBA/SNMP gateway

ORB

HTML JAVA Applet JAVA Applet WEB Browser

CORBA/SNMP gateway

SNMP Sub-domain

Agent AgentAgent

CORBA Sub-domain

Agent AgentAgent

CMIP Sub-domain

Agent AgentAgent

HTML(CGI) CORBA (Orbix Web)

RMI

망관리에서의 분산화 망관리에서의 분산화 : : Event Notification/M-ActionEvent Notification/M-Action

NMS

ServerServer Server

Notification M-Action

Action

NM client 의 load 를 줄여줌

Event filtering / Correlation 이 요구됨

Event 발생은 미리 작성된 Scenario 에 의함

Event 발생에 대한 reaction은 NMS 에 의존하므로 신속한 대응 미흡

망관리에서의 분산화 망관리에서의 분산화 : RMON: RMON

RMON 1- Subnetwork-wide 통계 제공- Off-line 관리 (data gathering)- alarm defing and event reporting- frame filtering and capturingRMON 2- End-to-End 통계자료 제공 • email, file transfer.www 에 따른 응용계층 트래픽을 감시 • host 들에서 특정 application 의 트래픽을 기록 가능단점 RMON 장비의 CPU, memory 낭비

- Network-layer address 에 근거한 통계자료 모음 (nlHOST) • Control table

Subnet SpecSubnet Spec

XY

• Data Table

Host related statistics

Host related statistics

# of input packets / octets# of output packets / octets

•••

Host related statistics

Host a Host b Host c

RMON Probe NMS

Host d Host e

Subnet X

Interface 2

Interface 1

Subnet Y

망관리에서의 분산화 망관리에서의 분산화 : Mobile Agent: Mobile Agent

NMS

Server

Script(code, data, state)

지적능력을 스스로 갖고 새로운 프로세스를 만들어 낼 수 있다 (Autonomy) Server 간에 이동이 가능하다 (Mobility) (remote execution 또는 migration)분산된 일을 server 를 지나며 수행 가능 (Intelligence)비동기적으로 망 관리 수행 가능 (Asynchronousity)망 관리에서 확장성과 유연성을 중대시한다 표준화그룹 : FIPA, OMG MASIF Platform : Aglet,Concordia,grasshopper, Voyager

Distributed Management : Management by Delegation (MbD)

Server

Server

Results

* FIPA : Foundation for Intelligent Physical Agent

* OMG : Object Management Group

* MASIF : MOBILE Agent System Interoperability Facility

Distributed ObjectsDistributed Objects

Common Object Request Broker Architecture Web-Based Enterprise Management

Java Management eXtensions

CORBA (1)CORBA (1)

Object Management Architecture standardized by OMG

Joint Inter-Domain Management (JIDM) group Sponsored by Open Group and the TMF

(Telecommunication Management Forum) Provide tools that enable management system based on

CMIP, SNMP, and CORBA to work together. Provide CMIP/CORBA and SNMP/CORBA inter-working. Map between GDMO/ASN.1 and CORBA IDL. Map between SNMP SMI and CORBA IDL.

CORBA (2)CORBA (2)

Web 기술과의 통합을 시도 Orbix Web from IONA CorbaWeb from academia

SNMP domain

Middleware(ex. ORB) Middleware(ex. ORB)

SNMPSNMP CMIPCMIP IDLIDL

ASN.1Objects

Manager

CMIP domain CORBA domain

GDMOObjects

CORBAObjects

Stub Skeleton

Network

Client(Caller)

Object(Callee)

Object Request Broker (ORB)

WBEMWBEM

Desktop Management Interface(DMI) 에서 제기됨 Web-Based Enterprise Management (WBEM)

초기에는 HMMS, HMMP, and HMOM 로 구성됨 Drastic upheaval of WBEM

Common Information Model (CIM) CIMOM 이 HMOM 을 대치 . HTTP 과 XML 을 수용함 . Current work

Integrating CIM with CORBA and Java-based management. Developing SNMP/CIM, DMI/CMI, and CMIP/CIM gateway.

Java technologiesJava technologies

Java RMI Can be combined with Object Serialization. Management objects (SNMP or CMIS/CMIP objects) are mapped int

o distributed Java objects. JMAPI (Java Management API)

Based on Java RMI Set of tools and guidelines to build management applets. Supports the most common SNMP MIB (MIB-II)

JMX (Java Management eXtension) A management framework destined for object-oriented web-based m

anagement. SNMP API, WBEM API, (already specified) and TMN API (currently un

der definition) SNMP-to Java MIB compiler (translates the managed objects into M

Bean Component)

JMXJMX

JMX Architecture Instrumentation level : give instant manageability to any

object Agent level : provide management agent. Manager level : provide management component

operating as manager or agent. JMX Components

JMX Manageable Resource JMX Agent JMX Manager Services for management Addition Management Protocol APIs

Interacting with other management environments.

Key Component of JMXKey Component of JMX

ManagerLevel

AgentLevel

InstrumentationLevel

Proprietary Management Application Web Browser

Proprietary Management Application

JMX Manager

MBeanServer

Service

Object 2

Object 1

Object 3Java virtual machine Java virtual machine

ProtocolAdaptors

MBean (registered in the server) Plain JavaBeans Component (not registered)

AgentX (Agent Extensibility Protocol)AgentX (Agent Extensibility Protocol)

Motivation for AgentXMotivation for AgentX

Distributed management 의 필요성 Hierarchical framework.

Management applications 의 분산된 agent 에 대한 투명한 접근 Managed objects 의 동적인 확장

MIB 장비로부터 SNMP protocol engine 을 분리 MIB 구현 모듈의 동적인 추가

AgentX FrameworkAgentX Framework

ManagerSNMPEntity

AgentXDispatcher

Sub-Agent

Sub-Agent

Sub-Agent

AgentX Master-Agent

Extensibilityprotocol

SNMP

Master agent Agent 역할로서 SNMP

프로토콜 메시지의 송수신 . MIB 에는 거의 직접적으로

접근하지 않음 . Subagent(s)

Master-agent 에 의해 처리되는 SNMP 메시지로부터 “ Shielded” 됨 .

MIB 을 직접 접근 .

AgentX Roles – Master AgentAgentX Roles – Master Agent

기능 Subagent 로부터 AgentX session 확립 요구를 받아들임 . Subagent 로부터 MIB region 의 등록 접수 현재 등록된 MIB region 에 따라 , AgentX 프로토콜이 MIB 에 접근 Subagent 를 위해 notification 을 전달해줌 .

AgentX Roles - SubagentAgentX Roles - Subagent

기능 Master-agent 와 함께 AgentX session 시작 Master-agent 에게 MIB region 을 등록 등록된 MIB region 내에서 OID 와 실제 variable 을 bind 시킴 Variable 에 대한 관리 동작을 수행 관리 객체 (MO: Managed Object) 를 초기화 시킴 Notification 을 주도

Example: Management with AgentXExample: Management with AgentX

Master Agent

MIB Registry

Mail Server

Email MIB

Subagent

WWW Server

WWW MIB

Subagent

10baseT Hub

Repeater MIB

Subagent

AgentX

AgentX

AgentX

NMSSNMP

From a manager’s point of view, an extensible agent behaves exactly as would a monolithic agent.

The master agent is MIB ignorantand SNMP omniscient while the subagent is SNMP ignorant and MIB omniscient.

AgentX Protocol OperationsAgentX Protocol Operations

18 Protocol operations are defined. 7 PDUs for Master agent Subagent direction

10 PDUs for Subagent Master agent direction

1 PDU for both Master agent and subagent.

Master agent Subagent Get-PDU, GetNext-PDU, Get-Bulk-PDU, TestSet-PDU, CommitSet-

PDU, UndoSet-PDU, and CleanupSet-PDU.

Subagent Master agent Open-PDU, Close-PDU, Register-PDU, Unregister-PDU, Notify-PDU,

Ping-PDU, IndexAllocation-PDU, IndexDeallocation-PDU, AddAgentCaps-PDU, and RemoveAgentCaps-PDU.

Both side Response-PDU

OID RegistrationOID Registration

Subagents may register single instances: E.g., 1.3.6.1.2.1.25.1.2.0 = HOST-RESOURCES-

MIB.hrSystemDate.0

Subagents may register OID regions: E.g., 1.3.6.1.2.1.2.2.1.[1-22].7 = IF-MIB.ifIndex.7 – IF-

MIB.ifSpecific.7

Only a single subagent can be “authoritative” for a particular OID region. Priority values are used to identify the authoritative

subagent if regions overlap.

Transport Layer MappingsTransport Layer Mappings

AgentX defines the following transport mappings: AgentX over TCP

The master agent accepts TCP connection requests for the well-known port 705.

Subagents connect to the master agent using 705 port number.

AgentX over UNIX-domain Sockets The master agent creates a well-known UNIX-domain socket

endpoint called “/var/agentx/master”.

AgentX PDUs are not encoded using the BER They are transmitted as a contiguous byte stream. (Unlike

SNMP PDUs)

Security ConsiderationsSecurity Considerations

Agent session 동안 SNMP 보안 관련 정보가 subagent 에게 전달되는 방법이 없다 .

NMSMasterAgent

SubagentCommunity

USEC for v3

No mechanism

Implementations and ProductsImplementations and Products

JAX – A Java AgentX Sub-Agent Toolkit http://www.ibr.cs.tu-bs.de/projects/jasmin/jax.html

CMU AgentX Implementation http://www.net.cmu.edu/groups/netdev/agentx/

Compaq True64 UNIX version5.0 mailto: daniele@zk3.dec.com

Epilogue Envoy http://www.isi.com

UC Davis, SNMP suites ucd-snmp.ucdavis.edu

Frank Fock, Agent++ http://www.fock.de/agent++

AgentX LimitationsAgentX Limitations

Requires relatively complex operations on the master agent side in order to realize SNMP lexicographical ordering and access control efficiently.

Only a single subagent can be “authoritative” for a particular OID regions. Only one network device which has same MIB can be

managed at the same time.

Security mechanism is not considered.

Functional MIBsFunctional MIBs

Expression MIBEvent MIB

Scheduling MIBRemote Operations MIBs

Notification Log MIB

Expression MIBExpression MIB

목적 : 망관리 시스템에서 네트워크 트래픽 overhead 를 줄이기 위함

MIB variable 에 대한 expression computation 수행 Expression 구성시 3 가지 MIB object sampling 형태 지원

absolute, delta, changed (boolean sampling).

Information about a single expression(Interval, Prefix…)

expExpressionEntry

Information about errors in processing

an expression

expErrorEntry

A table of object definitions for each expExpressionEntry

row(OID, wildcard…)

expObjectEntryA table of values from evaluated

expressions

expValueEntry

Used by

ProduceResult

ProduceError

Event MIBEvent MIB

목적 MIB variable 이 threshold 를 지나치거나 , 변화된 값을 가질 때

event 를 발생시키기 위함 다른 MIB 과의 관계

[RFC1757] RMON alarm, event group 의 능력에 대한 superset 제공

[RFC1905] SNMPv2 의 Manager-Manager MIB 의 계승 / 보완 [RFC2573] SNMPv3 Management Target 과 Notification MIB

의 서비스에 의존 [RFC2982] 분산 관리 Expression MIB 을 보완한다 .

Scheduling MIBScheduling MIB

목적 주기적 또는 주어진 날짜와 시간에

수행될 action 에 대한 scheduling

동작 Control object 를 변경시켜

schedule 을 enable/disable 시킴

다른 관리 기능에 의해 활성화 /비활성화 되는 schedule 을 미리 구성할 수 있게 함 .

schedEntry

schedOwner SnmpAdminString, schedName SnmpAdminString, schedDescr SnmpAdminString, schedInterval Unsigned32, schedWeekDay BITS, schedMonth BITS, schedDay BITS, schedHour BITS, schedMinute BITS, schedContextName SnmpAdminString, schedVariable VariablePointer, schedValue Integer32, schedType INTEGER, schedAdminStatus INTEGER, schedOperStatus INTEGER, schedFailures Counter32, schedLastFailure SnmpPduErrorStatus, schedLastFailed DateAndTime, schedStorageType StorageType, schedRowStatus RowStatus

Remote Operations MIBsRemote Operations MIBs

Ping MIB Remote host 에서 관리 응용으로 하여금 Ping 수행 가능케 함 .

Traceroute MIB Remote host 에서 Traceroute 수행케 함 .

Lookup MIB Remote host 에서 Name lookup 가능케 함 .

Notification Log MIBNotification Log MIB

목적 Local loggin 기능의 형태로 다른 MIB 에게 common infrastructure

제공 주로 sender 의 Notification 을 위해 사용되나 receiver 도 사용 가능 .

A table of Notification log statistics entries(logged or bumped)

nlmStatsLogEntry

A table of variablesto go with Notification

log entries (values…)

nlmLogVariableEntry

A table of logging control entries.

(entry limit, filter…)

nlmConfigLogEntryA table of Notification

log entries(variables…)

nlmLogEntry

statistics

contains

has

Script MIBScript MIB

Overview of the Script MIB(1)Overview of the Script MIB(1)

Defined in RFC2592 SNMP-compliant MIB Script MIB

분산된 장소로 Script 전달 Script 를 위한 argument 전달 동작중인 script 의 monitor, control 이 원격으로 가능 Running script 로 부터 결과 받음 .

Overview of the Script MIB(2)Overview of the Script MIB(2)

• Consists of six tables– Language– Extension– Script– Code– Launch– Run

• OID is (mib-2 64)

scriptMIB(mib-2 64)

smObjects

smLangTable

smExtsnTable

smScriptObject

smScriptTable

smCodeTable

smRunObjects

mib - II

smLaunchTable

smRunTable

Table (1)Table (1)

Language Table Agent 가 지원하는 언어 정보 제공 . E.g. Java, and Tcl etc.

Extension Table Language 확장에 대한 정보 제공 Local resource 나 network protocol 에 대한 interface 제공 가능 .

Table (2)Table (2)

Script Table Script MIB 을 지원하는 network 장비에 설치된 모든 script 를 나열 Script 를 설치 / 제거 , script 상태를 변경 / 읽기 등을 가능케하는 o

bject 가짐 . 지정된 URL 로 부터 script 를 Agent 에 의해 영원히 설치되고 ,

받아질 수 있음 . Code Table

SNMP set operation 에 의해 Agent 에게 script 를 도착하게 (push) 함 .

Table (3)Table (3)

Launch Table 준비된 script 를 서술 List 의 각 entry 는

Script 에서 전달된 argument Script 수행중의 신뢰도 , 허가등을 나타냄 .

Run Table 최근 끝나거나 , 돌고 있는 script list Manager 로 하여금 동작되고 있는 script 에 대한 정보 추출이나

제어 가능케 함 .

Operations of Script MIBOperations of Script MIB

smLangTablesmLangTable

JavaJava JDK1.1.8JDK1.1.8

PerlPerl 5.0045.004

smScriptTablePre-

installed Info AccessⓢPre-

installed Info AccessⓢDynamic-loaded Info Accessⓢ

Dynamic-loaded Info Accessⓢ

smLaunchTable

secutiryⓢ

ⓢ

ⓢ

ⓢ

args

args

args

args

secutiry

secutiry

secutiry

Launch

Launch

Launch

Launch

smRunTable

stateⓢ

ⓢ

ⓢ

ⓢ

args

args

args

args

state

state

state

result

result

result

resultNetwork

Node

SNMP agent

Manager Script Repository

SNMPpush script

HTTP or other

HTTP

①

②

③ ④⑤

pull script

Applications of Script MIBApplications of Script MIB

Scripts as Agent Scripts as Mid-level manager

Monitoring Service testing (QoS monitoring) Service management and control Fault handling

Scripts as AgentScripts as Agent

Agent 를 확장하거나 구현 표준 MIB 로 부터 관리정보를 computing 하는 서비스

제공 Agent 의 확장성 제공 .

managermanager

Internet Server

Script MIBagent

Script MIBagent

MIB-II(ex. tcpConnTable)

MIB-II(ex. tcpConnTable)

ScriptRepository

ScriptRepository

Launch script

Retrieving result

Polling

response

Scripts for monitoringScripts for monitoring

Monitoring Detecting irregular

condition Collecting accounting data

More scalable The number of node to be

monitored MIB objects per node

Significantly decrease management traffic. Pre-process monitored data

More flexible Easy to add nodes to be

monitored Easy to modify the set of

MIB objects monitored.

managermanager

M

AM

A

AA AA AAAA

mid-levelmanager

M : ManagerA : Agent

Script for service testingScript for service testing

Service testing (QoS monitoring) Checking the availability and

the static and dynamic parameters of a given services.

Introducing new MIB module Lacks flexibility for new

services Service testing by Script MIB

Rapidly adaptable to new situation.

Script MIB agent is located where potential users are (differ from central manager).

Script MIB can be installed on several remote location which require service monitoring.

InternetServer

Receiveservices

Send test packet

UserAgent

manager

result

MIB

Launchscript

Script for service deployment and Script for service deployment and controlcontrol

Local mid-level managers can control server

processes are running on the same

node as the processes. The Script MIB offers a

convenient solution for the rapid development and installation of network services.

example) Remote service

deployment on programmable switch.

manager

Webserver

Check service

Download script

Control networkProgrammableswitch

Scripts for fault handlingScripts for fault handling

Fault handlings can be distributed to mid-level manager as script.

Central manager only required to decide which fault handling procedure to apply.

Procedures① Fault identification② Choose adequate script③ Install script④ Start and execute script⑤ Remove script

manager

Web server(repository)

①Fault notification

②ChooseAdequate script

③Install script

④Execution⑤Remove script

References (1)References (1)

Sun, “Java Management Extension White Paper,” http://java.sun.com/products/JavaManagement

WBEM Initiative, Online: http://www.dmtf.org/wbem CORBA, Online: http://www.omg.org/ M. Daniele et al., “Agent Extensibility (AgentX) Protocol Version

1,” , RFC2741, January 2000. L. Heintz et al., “Definitions of Managed Objects for Extensible S

NMP Agents,” , RFC2742, January 2000. R. Kavasseri and Bob Stewart, “Event MIB,” , RFC2981, October

2000 R. Kavasseri and Bob Stewart, “Distributed Management Epressi

on MIB,” , RFC2982, October 2000.

References (2)References (2)

Bob Stewart and Ramanathan R. Kavasseri, “Notification Log MIB,” , internet draft, draft-ietf-disman-notif-log-mib-16.txt, February 2000.

Kenneth White, “Definitions of Managed Objects for Remote Ping, Traceroute, and Lookup Operations,” , RFC2925, September 2000.

D. Levi and J. Schönwälder, “Definitions of Managed Objects for Scheduling Management Operations,” , RFC2591, May 1999.

D. Levi and J. Schönwälder, “Definitions of Managed Objects for the Delegation of Management Scripts,” , RFC2592, May 1999

References (3)References (3)

J Schönwälder, “Emerging Internet Management Technologies,” IM’99 Tutorial, 1999.

Jürgen Schönwälder, Jürgen Quittek and Cornelia Kappler, “Building Distrubuted Management Applications with the IETF Script MIB,” IEEE Journal on Selected Areas in Communications, vol. 18, no. 5, May 2000.

David Levi, “Introduction to the Script MIB,” Simple Times, vol. 7 no. 2, Nov. 1999.

Éamonn McManus, “Script MIB Implementation Experience,” Simple Times, vol. 7 no. 2, Nov. 1999.

Frank Strauß, “Script MIB Performance Analysis,” Simple Times, vol. 7 no. 2, Nov. 1999.

Jürgen Quittek and Cornelia Kappler, “Practical Experiences with Script MIB Application,” Simple Times, vol. 7 no. 2, Nov. 1999.