Basic Ingredients
of Network Management
Woraphon Lilakiatsakun
Basic components
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Fig 3-1
Network devices
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A NE (network element) must offer a
management interface for management
purposes
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Allow managing system to send requests (
configure, retrieve statistical data and etc)
Send information (response and unsolicited )
Manager – a managing application who in
charge of the management
Agent – a NE who support the manager by
responding its requests
Manager-agent
communication
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Fig 3-2
Management agent
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Consists of 3 parts
A management interface
A Management Information Base
The core agent logic
Management interface
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Support a management protocol that
define rule of conversation
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Communication between the managed
network element
For example
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To open management session
To request to retrieve statistical data
To request to change configuration
Management Information Base
(MIB)
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Conceptual data store (management
information) that contain management view
of devices
A type of database used to manage the
devices in a communications network. It
comprises a collection of objects in a (virtual)
database used to manage entities (such as
routers and switches) in a network. (Ref. from
wikipedia)
MIB related standard
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RFC 1155
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RFC 1157
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Structure and Identification of Management
Information for TCP/IP based internets
Simple Network Management Protocol
RFC 1213
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Management Information Base for Network
Management of TCP/IP-based internets
MIB – OID Tree
OID = 1.3.6.1
(internet)
OID = 1.3.6.1.4.1.2682.1
(dpsAlarmControl)
Core agent logic
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Translates between the operation of the
management interface, MIB, and actual
device
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Ex. Translate the request to “retrieve a counter”
into internal operation that read out a device
hardware register.
Additionally, it can include more management
functions that offload the processing required
by management app.
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Pre-correlated raw events before sent out
An anatomy of management
agent
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Fig 3-4
Management information (1/2)
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The version of installed software
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Utilization of port
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Whether capacity upgrades are necessary
Environmental data (temperature and
voltage)
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To decide which devices need to have new
software
Ensuring that a device is not overheating
Fans
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What is causing the temperature to rise
Management information (2/2)
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Packet counters for different interfaces
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Protocol timeout parameter
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To fine tune network communication performance
Firewall rules
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Whether the network is under a certain type of
attacks (DoS)
Security purposes
others ?
Managed object (MO)
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Refer to “ a chunk of management
information that exposes one of the real
world aspects”
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Ex. MO could represent a device fan along with its
operational state, a port on a line card along with
a set of statistical data
MO could be
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a MIB object in SNMP
a parameter in a CLI (command-line interface)
An element of an XML document in web-based
management interface
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Not all aspects in the real world are modeled
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Color of devices
Real world object that MO represents is
referred to as the “real resource”
Since management information in MIB
represents real resource
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When querying the MIB for MO representing a
packet counter 3 times, the value returned will be
different
Basic parts of network
management - refined
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Fig 3-6
The Management System
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Tools to manage the network
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monitor the network
Service provisioning system
Craft terminal
In fact, management system is different
from management applications
But often we can use both as the same
meaning
Manager/agent reference
diagram
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Fig 3-8
Caching MIB
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Fig 3-9
The Management network
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Networks for carrying traffic of
subscriber or end user are referred as
“production network”
Networks for carrying management
traffic are referred as “management
network”
Both can be physically separate
networks or they can share the same
physical network
Connecting a craft terminal to
a managed device
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Fig 3-10
Connecting to multiple devices
through a terminal server
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Fig 3-11
Dedicated Vs Shared
Management and Production
networks
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Fig 3-12
Pros of a dedicated
management network
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Reliability
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Interference avoidance
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Compete with production traffic
May interfere high QoS services (voice ,video streaming)
Ease of network planning
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Congestion or network failure occurs somewhere in the
network, it makes the devices hard to reach
Also hard to find out what it happen
No need to consider on management traffic
Security
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Hard to attack and more secure
Cons of a dedicated
management network
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Cost and overhead
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Addition cost for a management network
No reasonable alternative
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Some devices do not provide a physical
connection for another usage
DSL router cannot be connected with two
physical links
Final word
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Cost is the huge disadvantage
So, the management network is needed
only critical area
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Backbone of service providers or big
enterprises)
Hybrid solution
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Generally, it shares over production
networks
Only critical segments are used as
dedicated networks
Managing the management
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The management support org. is responsible
for making sure that the network is being run
efficiently and effectively
These tasks must be performed
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Monitoring the network for failures
Diagnosing failures and communication outages
Planning and carrying out repairs
Provisioning new services and adding/removing
users
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Keeping an eye on performance of the
network
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Planning network upgrades
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Taking preventive measure
Increase capacity
Planning network topology and buildout
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Ensure that the network will meet future
demand
Organization structure
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Network planning
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Network operation
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Keeping the network running and monitoring the
network failures
Network administration
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Analyzing network usage and traffic patterns and
planning network build out
Installing new devices / software
Customer (user) management
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Interacting with the customers
Other thing are needed
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Establishment of process and
operational policies, documentation of
operational procedures
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Well-defined procedures
Well-defined workflow
Make management consistent and efficient
Collection of audit trails
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Automatically logging activities of
operations
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Network documentation
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Reliable backup and restore procedures
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Must be accurate and up-to-date
Important for network planning and software
upgrades
Identify some discrepancies
Bring network back to live again in case of
disaster
Security emphasis
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Networks potentially most vulnerable from the
inside
Limit the damage that can cause by one person
Management life cycle
Deploy
Plan
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Operate
Decommission
Plan
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Before the network system starts
During the network system is running
Management life cycle
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Deploy
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Operate
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Installation of the equipment
Bootstrap mechanism to allow a device to obtain
and IP address and have layer2 or 3 connectivity
Monitoring/troubleshooting/performance tuning
and etc
Decommission
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Old equipments (old technology) will be replace
TMN-layer: a management
hierarchy reference model
Business
Management
Service
Management
Network Management
Element Management
Network Element
Management layer
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TMN (telecommunication Management
network)
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Network element
Element management
Network management
Service management
Business management
Network element
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It means “the management agent “
It involves with
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the management functionality
Communication pattern (protocols)
Element management
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Involve managing the individual devices
and keep them running
Functions such as
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to view and change a network element’s
configuration
To monitor alarm messages emitted from
elements
To instruct network elements to run selftest
Network management
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Concern with keeping the network
running as a whole (end-to-end)
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Monitoring that involves ensuring that data
flow to reach destination with acceptable
throughput and delay
Managing multiple devices in a concerted
fashion
Service management
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Managing the services that the network
provides and ensuring those services
are running smoothly
Let’s think as ISP (Internet service
provider)
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?
Business management
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Billing and invoicing
Help desk management
Business forecasting
Etc ?