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byBehzad Akbari

Fall 2011

In the Name of the Most High

New Trends in Network Management

Need for new management technologies Since late ’80s

Networks have evolved Management needs have changed Management technologies have evolved

Mismatch in speed of evolution of networks and management requirements vis a vis management technology

Evolution of networks In the mid-late ’80s

Devices simple, resource constrained Capabilities were limited

Today Increased functional complexity Increased complexity in configuration Increased intelligence and programmability of devices Networks that provide a wide range of services NGNs: Packet based networks for all services Providing unfettered access for users to networks and

to competing service providers for services of their choice

Source: ITU-T Workshop on NGN (jointly organized with IETF) Geneva, 1-2 May 2005

Source: ITU-T Workshop on NGN (jointly organized with IETF) Geneva, 1-2 May 2005

Changes in operator needs Management of large backbone networks requires

powerful configuration management Move from device management approach to system

management Service centric view of network

VoIP (residential and business), multimedia streaming, IP TV, fast data connectivity, triple play

Increased speed of service delivery Automation of business processes

Consequences for management Rethinking management principles – integration of

independent developments Management support for delivering quality service Changes resulting from “user” focus as opposed to

“network” focus Importance of developing standardized management

software for easy maintenance and extensibility

Traditional approaches - Datacomm

SNMP based Aim was to have simple small footprint protocol Kept self contained and independent of other network

services Catered to fault, performance monitoring, simple

configuration management Soon after release, shortcomings were exposed

Key revisions in SNMP v2, v3

Revised OBJECT definitions counter64 type

Improved tables unambiguous row selection procedures for creation and deletion of rows augmenting of tables

Notification definition Manager-manager communication SNMP v3 - Security

Drawbacks of SNMP Inadequate information modeling – simple data

structures and protocol operations Object based rather than object oriented No inheritance – so no information re-use Inadequate primitive for bulk information retrieval UDP transport restricts size of data that can be sent Limited configuration management support Low level semantics

Configuration management needs Need to apply configuration changes to several network

devices simultaneously Download bulk configuration changes on many devices Schedule configuration operations on devices at

particular times Roll back support Co-ordinated activation of downloaded configurations

Overcoming SNMP shortcomings

Evolutionary efforts were made to address shortcomings Improving SMI Improving SNMP protocol Enhancing configuration management

capability

Evolutionary efforts - I

Internet Research Task Force (IRTF) and Network Management Research Group (NMRG) developed SMIng Allows arbitrarily nested data structures Facilitates re-usability of complex data structures Extensible mechanisms

IETF was to develop a standards track for above in 2000 Phase 1: requirements drawn up Phase 2: 2 strong proposals emerged

Efforts to merge these failed, in 2003, group was wound up

Evolutionary efforts - II

Attempt to improve protocol shortcomings Efforts to reduce overhead due to OID redundancy

Compression Suppression of redundant OID fragments Effect bulk transfer at MIB level instead of OID

Use of TCP as transport protocol Did not meet with success because of industry

reluctance to accept new technology

Evolutionary efforts - III COPS PR for improving Configuration Management

capability Resource Allocation Protocol (RAP) –WG for policy

based configuration and provisioning Specification language: Structure of Policy Provisioning

Information (SPPI) TCP is transport protocol Intends to make configuration changes based on PBMS

Selecting a management technology Information model

Defines how the management information is represented, data structures, objects etc. Eg., SNMP/UDP/IP is management protocol and SMI for definition of data

Communication model Defines protocol for exchange of management information,

structure of PDU, protocol operations Specifies how units of management information can be

addressed Organizational model

Actors, roles and principles of co-operation whether manager-agent, management by delegation, mobile agents, policy based etc.

Selecting a management technology

Efficiency and timeliness Simplicity Cost of development and maintenance Maturity Security Overhead on managed equipment (CPU,

memory footprint etc.) Bandwidth overhead

Characteristics of management data

MFA Realtime Bulk Read/Write

Fault Yes Yes Read

Performance Yes Yes Read

Configuration No Yes Read/Write

Security Yes Yes Read

Alternative management approaches Web based management embedded web server in device Browser can connect to to the URL of the device and

html pages with management information Provides graphical displays of management information Improved configuration facility, detailed device

management Drawbacks

More an EMS-like approach – no end to end view High level management functions such as map based

view, root cause analysis, trend analysis not supported

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Web Interface

NMS

SNMP Manager

Managed Objects SNMP Agent

Web Server

Web Browser

NMS Console

Desktop PC

Figure 14.1 SNMP NMS with Web Interface

SNMP

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Proxy Server

Proxy Server

ManagerApplications

Managed Objects SNMP / OtherAgent

Web Server

Web Browser

Desktop PC

Figure 14.2 Proxy Server with Web Interface

SNMP/Other

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Embedded WBM

ManagerApplications

Managed Objects Web Server

Web Browser

Workstation/PC

Figure 14.3 Embedded WBM Configuration

HTTP

Web based & SNMP Devices have an embedded web server as well as

SNMP agent (dual interface) Combines the advantages of both approaches

Manager agent paradigm Efficient Fault and Performance monitoring capability offered by

SNMP Detailed configuration Map based end-to-end view

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Desktop Management Interface

Service Layer (SL)Management Interface (MI)

Component Interface (CI) MIF DataBase

MIF: Management Information Format

Desktop ResidentManagement Applications

Hardware/Software Components

API

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Desktop Management Interface (DMI) Industry standard generated by

- Desktop Management Task Force (DMTF) Started in 1992 to manage PCs Manages both hardware and software Two standards

Management information format (MIF), similar to MIB

Program interface with two APIs

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DMI Service Layer

Synchronization and Flow Control

Management Interface

Component Interface

MIF Access

MIF Set

MIF Install MIF DataBase

Request/Confirms

Response/Confirms Events/Response

Indications

CommandProcessing

EventProcessing MIF Processing

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DMI Functions

DMI Service Provider SP/MIFDatabase

Management Interface Server

RPC Support

MI InterfaceClient

IndicationServer

RPC Support

MI InterfaceClient

IndicationServerLocal Block

InterfaceApplication

Data Block MgmtInterface

RPC SUPPORTIndication Client

Data Block ComponentInterface Procedural Component Interface

Block CIComponent(HW/SW)

Procedural CIHardware

Component

Procedural CISoftware

Component

Procedural CIFirmware

Component

RPC to/fromRemote Systems

Figure 14.6 DMI Functional Block Diagram

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DMI MIB

enterprises(1)

dmtf(412)

dmiMIB(1)

dmtfStdMifs(2)

dmtfDynOids(3)

dmiConformance(3)

dmiNotification(2)

private{1 3 6 1.4}

dmiObjects(1)

Figure 14.7 DMI MIB

• MIF specified using ASN.1 syntax• Can be managed by an SNMP manager• DMTF task expanded to specify WBEM -

Web-based enterprise management• DMTF

- Distributed Management Task Force

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Web-Based Enterprise Management Web Client

SNMPManaged Objects

DMI Managed Objects

DMI ProviderSNMP Provider

CIMObject Manager

(CIMOM)CIM

Schema

ManagementApplications

Web Browser

Desktop PC

HTTP HTTP

HTTP

SNMP RPC

CIM Managed Objects

HTTP

Figure 14.8 WBEM Architecture

SNMP Agent

DMI Agent

CIM Agent

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Web-Based Enterprise Management WBEM based on Common Information Module

CIM is information-modeling framework intended to accommodate all protocols and frameworks

Object-oriented Five components:

Web client CIM object manager (CIMOM) CIM schema Management protocol Managed objects with specific protocol

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Microsoft WMI

CIM Object Manager RepositoryMOF Language

COM/DCOM API

Object Providers

WMIObjects

WMI

SNMPObjects

SNMP

DMIObjects

RPC

Win 32Objects

Win 32

OtherObjects

COM/DCOMIWbemServices

ManagementApplications Snap-inSnap-in

COM/DCOMIWbemServices

Figure 14.10 WMI Architecture

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Microsoft WMI • WMI is Microsoft infrastructure to support WBEM

CIM• WMI comprises management infrastructure,

applications, and agents• CIMOM has plug-in management applications• COM/DCOM API specifies interface to CIMOM• CIM is the CIM schema• Object providers are management agents (e.g.

SNMP agent)

New Management Technologies

TeleManagement Forum(TMF) Interfaces MTNM

NML-EMS interface based on CORBA MTOSI

OS-OS interface based on XML

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