1. Fundamentals of Network Management

2. Network Management Standards
OSI
Common Management Information Protocol (CMIP)
International standard (ISO / OSI)
Management of data comm. Network LAN and WAN
Deals with all 7 layers
Most complete
Object oriented representation
Well structured and layered
Consumes large resources in implementation
Internet
Simple Network Management Protocol (SNMP)
Industry standard (IETF)
Originally intended for management of Internet components, currently adopted for WAN and telecom systems.
Easy to implement
Most widely implemented NM standard.
Lacks advanced functionality (compared to CMIP)

3. Network Management Standards (…)
Telecommunication Management Network (TMN)
International standard of the ITU-T
Management of telecom networks
Based on the OSI network management framework
Addresses both network, administrative, and business aspects of management.
IEEE
Addresses LAN and MAN management.
Deals with the first 2 layers.
Web-based Management
Web-based Enterprise Management (WBEM)
Java Management Application Program Interface (JMAPI)

4. Management Architecture
This architecture is used for both OSI and SNMP-based management
Consists of a number of models

5. OSI Models Organization Information Communication Functions
Network management components
Functions of components
Relationships
Information
Structure of Management Information (SMI)
Syntax and semantics
Management Information Base (MIB)
Organization of management information
Communication
Transfer syntax with bi-directional messages
Transfer structure (PDU)
Functions
Application functions
Configure components
Monitor components
Measure performance
Secure information
Usage accounting

6. SNMP Architecture and Models
Organization
Same as OSI model
Information
Same as OSI, but scalar
Communication
Messages less complex than OSI and unidirectional
Transfer structure (PDU)
Functions
Application functions
Operations
Administration
Security

7. Organizational Model Manager Agent Managed object
Sends requests to agents
Monitors alarms
Houses applications
Provides user interface
Agent
Gathers information from objects
Configures parameters of objects
Responds to managers’ requests
Generates alarms and sends them to mangers
Managed object
Network element that is managed
Houses management agent
All objects are not managed / manageable

8. Organization Model Manage objects can be Managed object
Network elements (hardware, system)
hubs, bridges, routers, transmission facilities
Software (non-physical)
programs, algorithms
Administrative information
contact person, name of group of objects (IP group)
Houses SNMP management agent
Objects are classified into managed/unmanaged
Managed object has a running management agent
Manager
Managed objects
Unmanaged objects
Two-Tier Network Management Organization Model
Agent process
MDB
MDB Management Database

9. Organization Model Management Station (Manager)
Interface for network managers to monitor and control the network
Contains management applications (data analysis, fault recovery, etc.)
Translation capabilities from manager’s requirements into actual monitoring and control of remote elements
Contains DB of information extracted from MIBs of all the managed entities in the Network
Manager
Managed objects
Unmanaged objects
Two-Tier Network Management Organization Model
Agent process
MDB
MDB Management Database

10. Organization Model Management Agent Gathers information from objects
Configures parameters of objects (e.g., enable/disable a router port, shut down a port on a hub, etc.)
Responds to requests for information and actions from managers
Generates alarms and sends them to managers
Manager
Managed objects
Unmanaged objects
Two-Tier Network Management Organization Model
Agent process
MDB
MDB Management Database

11. Organization Model Middle layer plays the dual role
Agent to the top-level manager
Manager to the managed objects
collects, processes and stores data locally
Performs statistical operation on the data and passes it to top level manager
The intermediate system could be at a local site and passes info. to a remote site.
Example of middle level: Remote monitoring agent (RMON)
Agent / Manager
Managed objects
Agent process
Manager
Three-Tier Network Management Organization Model
MDB
MDB Management Database

12. Organization Model Different network domains, each managed locally
MoM
Agent
Agent NMS
Manager
Managed objects
MDB
MoM Manager of Managers
NMS Network Management System
Different network domains, each managed locally
Agent NMS manages the domain
MoM presents integrated view of domains
Domain may be geographical, administrative, vendor-specific products, etc.

13. Dual Role of Management Process
Peer NMSs
Dual Role of Management Process

14. Communication Model
MIB
MANAGER
AGENT
SNMP
Resources are represented as objects (or data variables)
Collection of objects is a MIB (more later)
A manager performs monitoring by retrieving the value of MIB objects
A manager causes an action to take place or changes the configuration settings by modifying values of specific variables

15. Communication Model
MIB
MANAGER
AGENT
SNMP
Management stations and agents are linked by a network management protocol
SNMP is used for the management of TCP/IP networks
Get: manager or management station can retrieve the value of objects at the agent
Set: set the values of objects at the agent
Trap: agent notifies manager on significant events

16. Protocol Architecture
-SNMP uses UDP
port 161
- connection-less
(e.g., Ethernet, X.25, ATM)
Interprets SNMP messages
and controls the agent’s MIB

17. Communication Model
Management data is communicated between agent and manager as well as between managers
Three aspects:
Transport medium of message exchange (transport protocol)
Message format (application protocol)
Actual message (commands and responses)
Manager
Agent
Operations /
Requests
Responses
Notifications /
Traps
Applications
Network Elements
Managed Objects
Management Message Communication Model

18. Management application
Communication Model
Management application
Application
manages object
SNMP managed objects
GetRequest
GetNextRequest
SetRequest
GetResponse
Trap
Central MIB
GetRequest
GetNextRequest
SetRequest
GetResponse
Trap
Layer 1 & 2 IP
SNMP Manager
UDP
SNMP Agent
Network
SNMP Messages

19. Trap-Directed Polling
SNMP encourages the manager to use trap-directed polling
A manager may be responsible for a large number agents, each maintains a large number of managed objects
It is impractical to regularly poll all agents for all their readable objects (management overhead on the network may be very excessive!)
managing entity
agent
data
managing
entity
data
managed device
agent
data
network
management
protocol
managed device
agent
data
agent
data
managed device
managed device

20. Trap-Directed Polling
Initially a manager may poll all the agents for some key information
e.g., interface characteristics (# pckts in/out, etc..)
Then, each agent is responsible for notifying (through trap messages) the manager of any unusual event
e.g., high pckt drop rate at some interface
managing entity
agent
data
managing
entity
data
managed device
agent
data
network
management
protocol
managed device
agent
data
agent
data
managed device
managed device

21. Information Model
The representation of objects and information relevant to their management
This information is usually communicated between agents and management processes
SMI (Structure of Management Information) defines the syntax and semantics of management information stored in MIB (Management Information Base)
Example sysDescr: { system 1 } Syntax: OCTET STRING Definition: "A textual description of the entity. " Access: read-only Status: mandatory
MIB
Contains information about objects
Organized by grouping of related objects
Defines relationship between objects
Agent MIB vs. Manager MIB
MIB Agent: local information
MIB Manager: info. on all network components

22. Information Model MDB physical database; e.g.. Oracle
Contains measured or administratively configured values of NEs
MIB virtual database; schema compiled into management software
Info necessary for processes to exchange info. (e.g., #ports/hub)
A NMS can automatically discover (periodic broadcast of PING messages) a managed object, such as a hub, when added to the network
Once detected, its information (e.g., address, number of ports, etc.) is added to MDB
MIB does not need to be updated if another hub from same vendor already exist

23. Management Information Tree
Designation of objects:
iso 1
org 1.3
dod
internet
Both Internet and OSI define objects uniquely by a tree structure
Each managed object occupies a node in the tree underneath the root
iso-itu 2
itu
iso 1
org 3
dod 6
internet
OSI Management Information Tree
Root
Level 1
Level 2
Level 3
Management Information Tree
Standard organizations: define
management of objects under them
Managed Objects

24. Object Type and Instance
Object ID
and
Descriptor
circle
Access:
Access
privilege
Definition :
Semantics -
textual description
Status
Implementation
requirements
Syntax
model of object
Internet Perspective
object ID unique ID
and descriptor and name for the object
syntax used to model the object
access access privilege to a managed
object (read-only, etc)
status implementation requirements (e.g., optional or mandatory)
definition textual description of the
semantics of object type

25. Object Type and Instance
Behavior
Object Class:
Circular
object
Elliptical
Attributes: :
circle, dimension
Operations:
Push
ellipse, dimension
Notifications
Notify changes in
attribute values
OSI Perspective
object class managed object
attributes attributes visible at its boundary
operations access operations that can be applied to it
behavior behavior exhibited by it in response to an operation
Notifications notifications emitted by the object

26. Object Type and Instance

27. Functional Model Configuration management Security management
Set and change network configuration and component parameters
Set up alarm thresholds
Fault management
Detection and isolation of failures in network
Trouble ticket administration
Performance management
Monitor performance of network
Security management
Authentication
Authorization
Encryption
Accounting management
Functional accounting of network usage