1. Introduction to Network Management

2. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

3. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

4. The Case for Management
Remote User
Typical problem
Remote user arrives at regional office and experiences slow or no response from corporate web server
Where do you begin?
Where is the problem?
What is the problem?
What is the solution?
Without proper network management, these questions are difficult to answer
Regional Offices
WWW Servers
Corp Network

5. The Case for Management
Remote User
With proper management tools and procedures in place, you may already have the answer
Consider some possibilities
What configuration changes were made overnight?
Have you received a device fault notification indicating the issue?
Have you detected a security breach?
Has your performance baseline predicted this behavior on an increasingly congested network link?
Regional Offices
WWW Servers
Corp Network

6. Solving Problem Procedure
An accurate database of your network’s topology, configuration, and performance
A solid understanding of the protocols and models used in communication between your management server and the managed devices
Methods and tools that allow you to interpret and act upon gathered information
High Availability
Response Times
Security
Predictability

7. Introduction Network Management System (NMS)
Automatic versus human effort
Increased network size
Increased complexity
Heterogeneous equipment
Equipment from multiple vendors

8. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

9. Network Management Requirements
Ease of use
Security features
Restoral capability
Ability to delete/add
Ability to monitor network availability
Traffic rerouting
Improved automation
User registration
Improved reporting
Ability to monitor response time

10. Network Management Requirements
Control corporate strategic assets
Control complexity
Improve service
Balance various needs
Reduce downtime
Control cost

11. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

12. Introduction to SNMP Simple Network Management Protocol
Provides a tool
for multi-vender, interoperable network management
used across a broad spectrum of product types
include end systems, bridges, switches, routers and telecommunications equipment
TCP/IP based

13. Simple Network Management Protocol
A set of standards for network management
a protocol
a data base structure specification
a set of data objects
Advantages
Stability : definition remain fixed
Simplicity: removes the complexity
Flexibility : support arbitrary commands

14. SNMP Family SNMPv1 SNMPv2 Proposed in 1989 Proposed in 1993
Revised in 1995
An upgrade to SNMPv1
Add functional enhancements to SNMP and codify the use of SNMP on OSI-based networks

15. SNMP Family (cont.) SNMPv3 Issued in 1998
Define a security capability for SNMP and an architecture for future enhancements
Used with the functionality provided by SNMPv2 or SNMPv1

16. SNMP PDU format

17. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

18. OSI Management Functional Areas
Fault management
Configuration management
Accounting management
Performance management
Security management

19. Fault Management
The facilities that enable the detection, isolation, and correction of abnormal operation of the OSI environment
What is “a fault”?
An abnormal condition that requires management attention (or action) to repair
Indicated by failure to operate correctly or by excessive errors
Communication line is cut
A crimp in the cable
Certain errors may occur occasionally and are not normally considered to be faults

20. Fault Management When a fault occurs
Determine “exactly” where the fault is
Isolate the rest of the network from the failure
Reconfigure or modify the network to minimize the impact of operation
Repair or replace the failed components

21. User requirements for Fault Management
Fast and reliable problem resolution
Receive notification and correct the problem immediately
Requires rapid and reliable fault detection and diagnostic management
Provides fault tolerance
Redundant components and alternate communication routes
Fault management capability itself should be redundant
Keep informed of the network status
Reassurance of correct network operation through mechanisms that use tests or analyze dumps, logs, alerts, or statistics
Problem tracking and control
Ensure the problem is truly resolved and no new problems are introduced
Fault management should have minimal effect on network performance

22. Configuration Management
Configuration management is concerned with
Initializing a network
Gracefully shutting down part or all of the network
Maintaining, adding, and updating the relationships among components and the status of components themselves during network operation

23. Requirements for Configuration Management
The network manager needs the capability to
Identify initially the components that comprise the network
Define and change the connectivity of components
Define and modify default attributes, and load the predefined sets of attributes into the specified network components
Reconfigure a network for performance evaluation, network upgrade, fault recovery or security checks
End users want to inquire about the upcoming status of resources and their attributes before reconfiguration
Generate configuration reports
Periodic basis
Response for a request
Only authorized end users can manage and control network operation (software distribution and updating)

24. Accounting Management
The facilities that enable
charges to be established for the use of managed objects
costs to be identified for the use of those managed objects

25. Accounting Management
Network managers track the use of network resources by end user or end-user class
An end user or group of end users may be abusing its access privileges and burdening the network at the expense of other users
End users may be making inefficient use of the network, and network manager can assist in changing procedures to improve performance
The network manager is easier to plan for network growth if end user activity is known in sufficient detail

26. Requirements for Accounting Management
The network manager can specify
The kinds of accounting information to be recorded at various nodes
The desired interval between sending the recorded information to higher-level management nodes
The algorithms to be used in calculating the charging
Generate accounting reports
Provide the capability to verify end users’ authorization to access and manipulate the information

27. Performance Management
The facilities needed to evaluate
The behavior of managed objects
The effectiveness of communication activities
Functions of performance management
Monitoring
Tracks activities on the network
Controlling
Enables performance management to make adjustments to improve network performance

28. Issues of Performance Management
What is the level of capacity utilization?
Is there excessive traffic?
Has throughput been reduced to unacceptable levels?
Are there bottlenecks?
Is response time increasing?

29. To Deal the Issues of PM
The network manager focus on some initial set of resources to be monitored in order to assess performance levels
Appropriate metrics and values with relevant network resources as indicators of different levels of performance
The count of retransmission on a transport connection
Monitor many resources to provide information in determining network operating level
Collect and analyze information, and then using the resultant analysis as feedback to the prescribed set of values

30. User Requirements for Performance Management
End users want to know
The average and worst case response times
The reliability of network services
Performance statistics can help managers
Plan, manage and maintain large networks
Recognize potential bottlenecks in advance
Balance or redistribute traffic load by changing routing tables

31. Security Management
The facilities that address those aspects of OSI security essential to
Operate OSI network management correctly
Protect managed objects
Network resources
End user information
End users want to know
The proper security policies are in force and effective
The management of security facilities is itself secure

32. Issues of Security Management
Managing information protection, and access control facilities
Generating, distributing and storing encryption keys
Passwords, authorization or access control information must be maintained and distributed
Monitoring and controlling access to computer networks and to all or part of the network management information
SM involves with the collection, storage, and examination of audit records and security logs
The enabling and disabling of these logging facilities

33. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

34. Network Management Systems (NMS)
NMS is a collection of tools for network monitoring and control
Designed to view the entire network as a unified architecture
Addresses and labels assigned to each point
Specific attributes of each element and link known to the system
Single operator interface with a powerful but user-friendly set of commands
A minimal amount of separate equipment (hardware/software) is necessary
NMS software resides in the host computers and communications processors (bridges, routers)

35. Network Management Systems
The active elements of the network provide regular feedback of status information to the network control center
NMS for single vendor equipment versus for multiple-vendor network
Two or more network control centers are used
High availability (backup)
One center is idle or collecting statistics
The other center is used for control

36. Network Management System
NMA = network management application
NME = network management entity
Appl = application
Comm = communications software
OS = Operating system
NMA
NME
Appi
Comm OS
Network control
Host (manager)
Server
(agent)
Workstation
Router

37. Network Management Configuration
Network Management Element (NME)
Contains a collection of software devoted to the NM task in each network node
Collects statistics
Stores statistics locally
Responds to commands from network control center (manager)
Transmit collect statistics to manager
Change a parameters (a timer in a transport protocol)
Provide status information
Generate artificial traffic for testing
Send messages to network control center for significant changes in local conditions
Referred to as an agent
Agents are implemented in end systems and nodes

38. Network Management Configuration
Network Management Application (NMA)
Include an operator interface to allow an authorized user to manage the network
Respond to user commands
Display information
Issue commands to NMEs through the network
Communicate with and control NME in other nodes
Application-level network management protocol

39. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

40. Network Management Software Architecture
Three categories
User presentation software
Network management software
Communications and database support software

41. Architectural model of NMS

42. User Presentation Software
An interface in manager systems
Monitor and control the network
An interface in agent systems
Network testing and debugging
View or set parameters locally
Presentation tools
Organize, summarize, and simplify the information as much as possible to avoid information overload
Graphical presentations
User interface should be the same at any node, regardless of vender

43. Network Management Software
Three-layer architecture
Network management application layer
Application element layer
Network management data transport service layer

44. Network Management Software (Cont’)
Network management application
Provides services of interest to users
FCAPS
Each application covers a broad area of network management and should exhibit consistency over various types of configurations (LAN, WAN, ..)
Application elements
Implement primitive and general-purpose network management functions
Generating alarms or summarizing data
Implement basic tools used by one or more network management applications
Developed based on software reuse

45. Network Management Data Transport Service
The module consists of
A NM protocol used to exchange management information among managers and agents
A service interface to the application elements
Provides very primitive functions (get, set and trap)

46. Communication & Database Support Software
Network management software needs access to a local MIB, and to remote agents and managers
Local MIB at an agent contains
Information reflecting the configuration and behavior of this node
Parameters used to control the operation of this node
Local MIB at a manager contains
Node-specific information
Summary information about agents under control

47. Communication & Database Support Software
MIB access module
Include basic file management software that enables access to the MIB
Convert local MIB format to a standardized form across the NMS
Communications protocol stack
OSI or TCP/IP stack
Support the network management protocol
Support communications among agents and managers

48. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

49. Distributed Network Management
A centralized NMS enables the manager to maintain control over the entire configuration, balancing resource against needs and optimizing the overall utilization of resources
Why distributed network management?
The proliferation of low-cost, high power PCs & workstations
The proliferation of departmental LANs
Local control and optimization of distributed applications
Distributed computing
Architecture of distributed network management
Hierarchical architecture
Department-level managers
Manage downsized applications and PC LANs

50. Distributed Network Management
Benefits
Network management traffic overhead is minimized
Offers greater scalability
Eliminates single-point failure
Elements for hierarchical architecture
Distributed management workstations
Given limited access for monitoring and control
Manage the departmental resources
One central workstation (with a backup)
Global access rights to manage all network resources
Interact with less-enabled management stations

51. Distributed Network Management
Distributed management system architecture
Management clients
Provide the user access to management services and information
Provide a graphical user interface
May access one or more management servers
Management servers are the heart of the system
Support a set of management applications and a MIB
Store common management data models
Route management information to applications and clients
Managed network devices
Are managed directly by one or more management servers
Through a vendor-specific element manager or proxy
management servers are the heart of the system
support a set of management applications and a MIB
store common management data models and route management information to applications and clients
The devices that have the same network management protocol as the management servers contain agent software and are managed directly by one or more management servers
For other dives, management servers can only reach the resources through a vendor-specific element manager or proxy

52. Typical distributed management system architecture
Network
Management server
Management
application
MIB
Element
manager
Network resources ( servers, routers, hosts ) with management agents
Management clients ( PCs, workstations )

53. Outline Introduction Network Management Requirement SNMP family
OSI management function areas
Network management system
Network management software architecture
Distributed network management
Proxies

54. Proxies Why proxies? Operations of proxies
Older systems may not support network management standards
Small systems are not suitable to be implemented full-blown NME
Some components do not support agent software
Modems and multiplexers
Operations of proxies
Translate requests and responses among managers and the target system
Act on behalf of one or more other nodes

55. Proxy manager architecture
Server
stub
Client proxy
Protocol
stack
Proxy manager
Management
application
Client
Standard operations and event reports
Proprietary operations and event reports