Download Chapter 1 Data Communications and NM Overview

Data Communications
and
Network Management Overview
CS 695 Network Management Techniques
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Outline
• Analogy of telephone network
• Data and telecommunication network
• Distributed computing environment
• Internet
• Protocols and standards
• IT management
• Network and system management
• Current status and future of network
management
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Telephone Network
• Characteristics:
• Reliable - does what is expected of it
• Dependable - always there when you need
it (remember 911?)
• Good quality (connection) - hearing each
other well
• Reasons:
• Good planning, design, and implementation
• Good operation and management of
network
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Telephone Network Model
Regional Center
Class 1 switch
Regional Center
Class 1 switch
Sectional Center
Class 2 switch
Sectional Center
Class 2 switch
Primary Center
Class 3 switch
Primary Center
Class 3 switch
Toll Center
Class 4 switch
Toll Center
Class 4 switch
End Office
Class 5 switch
End Office
Class 5 switch
To other
Regional centers
Sectional centers
Primary centers
Toll centers
End offices
To other
Primary centers
Toll centers
End offices
To other
Class 4 toll points
End offices
Legend:
Loop
Direct Trunk
Toll-Connecting Trunk
V oice
V oice
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Figure 1.1 Telephone Network Model
Toll Trunk
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Operations Systems / NOC
• Monitor telephone network parameters
• S/N ratio, transmission loss, call blockage, etc.
• Real-time management of network
• Trunk (logical entity between switches) maintenance
system measures loss and S/N. Trunks not meeting
QoS are removed before customer notices poor
quality
• Traffic measurement systems measure call blockage.
Additional switch planned to keep the call blockage
below acceptable level
• Operations systems are distributed at central offices
• Network management done centrally from Network
Operations Center (NOC)
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Data and Telecommunication Network
Data communication network
Terminal
Terminal
Host
Modem
Modem
Loop
Loop
Modem
Loop
Voice
Voice
Telecommunication network
Figure 1.3CS
Data
and Telecommunication
Networks
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Management Techniques
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IBM SNA Architecture
Workstation
Workstation
Cluster
controller
Cluster
controller
Communications
controller
Communications
controller
Mainframe
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Figure 1.5 IBM Systems Network Architecture Model
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DCE with LAN
DCE.. Distributed Computing Environment
Workstation
Host
Workstation
Ethernet
Workstation
Host
(a) Hosts and Workstations on Local LAN
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LAN-WAN Network
LAN A
LAN B
Bridge /
Router
Bridge /
Router
Bridge /
Router
LAN C
WAN
communication link
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Client/Server Model
Request
Control
transf er
Client
Server
Control
transf er
Response
Figure 1.7 Simple Client-Server Model
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Client/Server Examples
Server
(a) Server with Multiple Clients
Client A
Client
(joe.stone)
Client Z
to [email protected]
Bridge
Mail server
Server
Domain
Name
Server
(b) Dual Role of Client-Server
(a) Server with Multiple Clients
Client
(joe.stone)
Figure 1.8 Client-Server in Distributed Computing Environment
to [email protected]
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Bridge
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Workstation
(Joe)
Mail Server
Workstation
Internetworking
Configuration
LAN A
Domain
Name
Server
LAN B
Bridge /
Router
Bridge /
Router
Bridge /
Router
LAN C
Gateway
WAN
Gateway
LAN X
Bridge /
Router
Bridge /
Router
Bridge /
Router
LAN Z
LAN Y
Workstation
PC (Sally)
Mail Server
Architecture, Protocols and Standards
• Communication architecture
• Modeling of communication systems, comprising
•
•
• functional components and
• operations interfaces between them
Communication protocols
• Operational procedures
• intra- and inter-modules
Communication standards
• Agreement between manufacturers on protocols
of communication equipment on
• physical characteristics and
• operational procedures
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Communication Architecture
User A
User Z
Peer-Protocol Interface
Application Layers
Application Layers
Transport Layers
Transport Layers
Physical Medium
(a) Direct Communication between End Systems
System A
Intermediate system
System Z
User A
User Z
Peer-Protocol Interface
Application Layers
Application Layers
Transport Layer
Transport Layers
Transport Layers
Conversion
Physical Medium
Physical Medium
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(b) Communication between End Systems via an Intermediate System
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OSI Reference Model
User / Application program
Layer 7
Application
Layer 6
Presentation
Layer 5
Session
Layer 4
Transport
Layer 3
Network
Layer 2
Data link
Layer 1
Physical
Physical
medium
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OSI Layers and Services
Layer
No.
Layer Name
Salient services provided by the layer
1
Physical
-Transfers to and gathers from the physical medium raw
bit data
-Handles physical and electrical interfaces to the
transmission medium
2
Data link
-Consists of two sublayers: Logical link control (LLC) and
Media access control (MAC)
-LLC: Formats the data to go on the medium; performs
error control and flow control
-MAC: Controls data transfer to and from LAN; resolves
conflicts with other data on LAN
3
Network
Forms the switching / routing layer of the network
4
Transport
-Multiplexing and de-multiplexing of messages from
applications
-Acts as a transparent layer to applications and thus
isolates them from the transport system layers
-Makes and breaks connections for connection-oriented
communications
-Flow control of data in both directions
5
Session
-Establishes and clears sessions for applications, and
thus minimizes loss of data during large data exchange
6
Presentation
-Provides a set of standard protocols so that the display
would be transparent to syntax of the application
-Data encryption and decryption
7
Application
-Provides application specific protocols for each specific
application and each specific transport protocol system
PDU Communication Model
End System A
User A
End System Z
User Z
UD
Application
(A) PCI
Presentation
(P) PCI
Session
(S) PCI
Transport
(T) PCI
Network
(N) PCI
Data link
(D) PCI
Application
UD
Presentation
(A) PDU
Session
(P) PDU
Transport
(S) PDU
(T) PDU
(N) PDU
Network
Data link
Physical
Physical
(D)PDU Data stream
Physical Medium
PDU: Protocol Data Unit
PDU
=
PCI
+
UD
Figure 1.14 PDU Communication Model between End Systems
PCI: Protocol
Control Information
UDn = PDUn+1
UD: User Data
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TCP/IP Based Networks
• TCP/IP is a suite of protocols
• Internet is based on TCP/IP
• IP is Internet protocol at the network layer level
• TCP is connection-oriented transport protocol
and ensures end-to-end connection
• UDP is connectionless transport protocol and
provides datagram service
• Internet e-mail and much of the network mgmt.
messages are based on UDP/IP
• ICMP part of TCP/IP suite
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Basic Networking Concept – OSI-TCP/IP
Comparison
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TCP vs UDP
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DTE-A
A
Gateway
N
DTE-N1
Z
N1
N2
A-N-Z Standard Network
N-N1-N2-N3 Subnetwork under Node N
DTE :
Data Terminating Equipment
System A
T
N
D
P
N3
(a) Network configuration
Gateway System N
Transport
Transport
SNICP
SNICP
SNDCP
SNDCP
SNDAP
SNDAP
Subnet system N1
Transport
SNICP
SNDCP-SN
SNDAP-SN
SNDCP-SN
SNDAP-SN
Data link
Data link
Data link-SN
Data link-SN
Physical
Physical
Physical-SN
Physical-SN
Network Medium
Subnetwork Medium
(b) Protocol Communication
SNA, OSI, and Internet
SNA
OSI
End User Application
Application
Presentation Services
Presentation
Data Flow Control
Session
Transmission Control
INTERNET
Transport
SNICP
Path Control
Network
Application Specific
Protocols
Transport
Connection- Connectionless: UDP oriented: TCP
Network
IP
SNDCP
SNDAP
Data Link
Data Link
Not Specified
Physical
Physical
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Application Protocols
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NM Case Histories
Repeater
Repeater
Repeater
Repeater
Bridge
ISP
Backup ServerMail Server
(a) Multi-Segment Bus LAN with Single Port Bridge Connection
Repeater
Repeater
Repeater
Repeater
Bridge
ISP
Backup ServerMail Server
(b) Dual Multi-Segment Bus LANs with Two-port Bridge Connection
Backup Server Mail Server
Hub
Hub
Hub
Bridge
ISP
(c) Multi-Segment Hub Configuration
Common Network Problems
• Loss of connectivity (Link, Node, Interface)
• Duplicate IP address (Procedural)
• Intermittent problems
• Network configuration issues
• Non-problems
• Performance problems
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Challenges of IT Managers
•
•
•
•
•
•
•
•
•
Reliability
Non-real time problems
Rapid technological advance
Managing client/server environment
Scalability
Troubleshooting tools and systems
Trouble prediction
Standardization of operations - NMS helps
Centralized management vs “sneaker-net”
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Network Management (NM)
Definition
OAM&P of Network and Services
OAM&P: Operations, Administration,
maintenance, and Provisioning)
Goal
To ensure that the users of a network receive
the IT services with the quality of service (QoS)
that they expect.
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Top-down View of NM functions
Network
Management
Network
Provisioning
Network
Operations
Network
Maintenance
Planning
Fault Management / Service Restoration
Fault Management
Design
Configuration Management
Trouble Ticket
Administration
Performance Management / Traffic Management
Network Installation
Security Management
Network Repairs
Accounting Management
Reports Management
Facilities Installation
& Maintenance
Inventory Management
Routine Network
Tests
Data Gathering & Analyses
Figure 1.21 Network Management Functional Groupings
TT
Trouble Ticket
NM Functional Flow Chart
NOC: Network Operation
Center
I&M: Installation &
Maintenance
Network
Users
Configuration Data
Management
Decision
New
Technology
Performance & Traffic Data
Engineering Group
- Network Planning &
Design
TT Restoration
Operations Group
NOC
I & M Group
-Network Installation &
Maintenance
- Network Operations
Fault TT
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Management Functional Areas, MFAs
Management Functional Areas, MFAs)
Fault Management
Configuration Management
Accounting Management
Performance Management
Security Management
ITU-T X.700
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FCAPS: The Industry Standard Definition
for NM
Level F - Fault detection and correction
Level C - Configuration and operation
Level A - Accounting and billing
Level P - Performance assessment and
optimization
Level S – Security assurance and
protection
ITU-M.3400
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(1) Fault Management
Fault Management (FM)
Detection of a problem, fault isolation
and correction to normal operation.
FM involves the following steps:
Discover the problem.
Isolate the problem
Fix the problem (if possible)

Use of Trouble-Ticket Systems
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Fault Management Functions
Maintain and examine error logs
Accept and act upon error detection
notifications
Trace and identify faults
Carry out sequences of diagnostic tests
Correct faults
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Fault Management
DNS
UNIX
...
User
PC
FDDI
....
RMON
Device
Firewall
/ Router ....
Internet
....
UNIX
PC
...
Mail
Server
WWW
Server
UNIX
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(2) Configuration Management
Configuration Management
The process of finding and setting up
(configuring) network devices.
CM identifies, exercises control over,
collects data from, and provides data to
networked systems.
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Configuration Management Functions
 Set the parameters that control the routine
operation of the networked system.
 Associate names with managed objects and
sets of managed objects.
 Initialize and close down managed objects.
 Collect information on demand about the
current condition of the networked system.
 Obtain announcements of significant changes
in the condition of the networked system.
 Change the configuration of the networked
system.
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Configuration Management : Auto Discovery
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(3) Accounting Management
Accounting Management (AM)
Tracking each individual and group user's
utilization of network resources to better ensure
that users have sufficient resources.
AM enables charges to be established for the
use of network resources, and the costs to be
identified for the use of those network resources.
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Accounting Management Functions
Inform users of costs incurred or
resources consumed.
Enable accounting limits to be set and
tariff schedules to be associated with the
use of resources.
Enable costs to be combined where
multiple resources are invoked to achieve
a given communication objective.
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(4) Performance Management
Performance Management (PM)
Measuring the performance of network
hardware, software, and media.
Examples：
Overall throughput
Percentage utilization
Error rate
Response time
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Performance Management Functions
Gather statistical information.
Maintain and examine logs of system state
histories.
Determine system performance under
natural and artificial conditions.
Alter system modes of operation for the
purpose of conducting PM activities.
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(5) Security Management
Security Management (SM)
The process of controlling access to information
on the networked system.
Security Management Functions
The creation, deletion, and control of security services
and mechanisms.
The distribution of security-relevant information.
The reporting of security-relevant events.
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Network Management Components
NMS
Network
Agent
Network
Agent
Network
Objects
Network
Objects
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Figure 1.24 Network Management Components
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Interoperability
NMS
Vendor A
Messages
Services & Protocols
NMS
Vendor B
Network
Agent
Network
Agent
Network
Agent
Network
Agent
Network
Objects
Network
Objects
Network
Objects
Network
Objects
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Interoperability (cont.)
Application
Services
Objects
Objects
Vendor A
Management
Protocol
Objects
Vendor B
Objects
Transport
Protocols
(b)Services
Services and
Protocols
& Protocols
CS 695 Network
Management Techniques
Figure 1.23 Network
Management
Dumbbell Architecture
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Network Management Model
Management
Station
MA
Management Operation
Response
Event
Network
Element
R
MO
Manager
Agent
Communication
Protocols
Communication
Protocols
Network
Legend：
MA: Manager Applications
R: Real Resource
MO: Managed Objects
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Components of Network Management
Manager
Agent
Network Management Protocol
Network Management Information
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Status and Future Trends
• Status:
• SNMP management
• Limited CMIP management
• Operations systems
• Polled systems
• Future trends:
• Object-oriented approach
• Service and policy management
• Business management
• Web-based management
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Management Pyramid
Business Management
Customer Management
Service Management
Distributed System Management
Network Management
Element Management
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Functional Areas
Network Types
Fault
Configuration
IN
Stages
Accounting
VPN
Corporate Network
Performance
Change
WAN
Operation
Security
MAN
LAN
Installation
Planning
Management Scope ?
Network Management
System Management
Data
Voice
Applications Management
Service Management
Eneterprise Management
Disciplines
Video
Multimedia
Information Types
Network Management Basics
network
PC
...
NM
UNIX
FDDI
....
Polling
Firewall
/ Router ....
Internet
Notification
RMON
Device
....
UNIX
PC
...
UNIX
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