Transcript Basic Ingredients of Network Management

Basic component of Network
Management
Woraphon Lilakiatsakun
Basic components
• Fig 3-1
The Network devices
• It is also called “Network Element (NE)”
• NE must offer a management interface to allow
managing system to communicate with
• So, NEs. have to run a process as “Management
Agent”
• Management communication
– Manager - a managing application who in charge of the
management
– (Management) Agent – support the manager by
responding to its requests and notifying unexpected
events
Manager-agent communication
• Fig 3-2
Management agent
• A management interface – handle
management communication
• A Management Information Base (MIB)conceptual data store (management
information) that contain management view
of the device being managed
• The core agent logic – translates between the
operation of the management interface, the
MIB and the actual device
Management interface
• The mean to connect to the agent
– Hardware Interface : Port , interface card
– Software Interface : Management protocol that
defines the rules of conversation for
communication between the managed network
element
Management Information Base (MIB)
(1)
• Management operations are directed against the
conceptual view
– Ex. The network ports of a NE could be represented as a table in an
imaginary database with each port having a corresponding entry in
the table
• MIB is not a real database ,it works as a proxy of the NE
that affects to the actual device
– EX. When MA modifies entry in the conceptual table , the actual
configuration of device is also changed
• MIB does not always have to resemble a conceptual table
depending on the management agent
– Extended Markup Language (XML)
– Set of Command-line parameters
Management Information Base (MIB)
(2)
Management Information Base (MIB)
(3)
• MIB related standard
• RFC 1155
– Structure and Identification of Management Information
for TCP/IP based internets
• RFC 1157
– Simple Network Management Protocol
• RFC 1213
– Management Information Base for Network Management
of TCP/IP-based internets
Management Information Base (MIB)
(4)
OID = 1.3.6.1
(internet)
OID = 1.3.6.1.4.1.2682.1
(dpsAlarmControl)
MIB – OID Tree
Core agent logic
• Translates between the operation of the
management interface, MIB, and actual device
– Ex. Translate the request to “retrieve a counter” into
an internal operation that reads out a device hardware
register.
• Additionally, it can include more management
functions (embedded management intelligence)
that offload the processing required by
management app.
– Pre-correlated raw events before sent out
– Schedule a periodic test function instead of sending
new test request each time.
An anatomy of management agent
• Fig 3-4
Management information
• Management information provides an
abstraction of the real-world aspects for
management purposes
– The version of installed software - to decide which
devices need to have new software
– Utilization of port - whether capacity upgrades are
necessary
– Packet counter for different interfaces – indicate
that a network is under attack (DoS)
Managed Object (1)
• We refer a chunk of management information
that expose of these real-world aspects as a
managed object (MO)
– A device fan along with its operational state
– A port on a line card along with a set of statistical
data
Managed Object (2)
Managed Object (3)
• Not all aspects in the real world are modeled
– Color of devices
• Real world object that MO represents is referred to as
the “real resource”
• Since management information in MIB represents real
resource
– When querying the MIB for MO representing a packet
counter 3 times, the value returned will be different
– When modifying information in the MIB to perform certain
updates , it will affect the real world.
Basic parts of network management refined
• Fig 3-6
The Management System (1)
• Tools to manage the network
– Monitor the network
– Service provisioning system
– Craft terminal
• A management system can run one or more hosts
– Distributed across several hosts
– Scalability
– More robust
The Management System (2)
• Roles in Network
Management System
– Manager / Agent
• Sometimes, one network
element can play two roles
as figure
The Management System (3)
• Fig 3-8
Manager/agent reference diagram
The Management System (4)
• Fig 3-9
Caching MIB
The Management System (5)
• Pros for caching MIB
– avoid having to go back to the NE repeatedly for
the same information
• Cons for caching MIB
– The cache is stale
The Management Network (1)
• 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
The Management Network (2)
• Fig 3-12
Dedicated Vs Shared Management and Production networks
The Management Network (3)
Simple Management
Connecting a craft terminal to a managed device
and use CLI to configure and troubleshoot
the network device
The Management Network (4)
• Fig 3-11
Connecting to multiple devices through a terminal server
The Management Network (5)
• Fig 3-12
Dedicated Vs Shared Management and Production networks
The Management network (6)
• Pros of a dedicated management network
• Reliability
– Congestion or network failure occurs somewhere
in the network, it makes the devices hard to
reach
• Management traffic will be impacted
• Hard to find out what it is happening
The Management network (7)
• Pros of a dedicated management network (Con’t)
• Interference avoidance
– Compete with production traffic –data or voice traffic
– Not high volume but bursty characteristics may interfere
high QoS services (voice ,video streaming)
• Ease of network planning
– No need to consider on management traffic
• Security
– Hard to attack and more secure
The Management network (8)
• Cons of a dedicated management network
• Cost and overhead
– Addition cost for a management network
• No reasonable alternative
– Some devices do not provide a physical connection for
another usage
– DSL router cannot be connected with two physical links
The Management network (9)
• Cost is the huge disadvantage
• So, the management network is needed
only critical area
– Backbone of service providers or big
enterprises
• Hybrid solution
– Generally, it shares over production networks
– Only critical segments are used as dedicated
networks
The Management Support
Organization: (1)
• In term of Network – Network Operation Center
(NOC)
• Telecommunication service provide refer to
management system as Operation Support
System
• The management support Org. is responsible for
making sure that the network is being run
efficiently and effectively
The Management Support
Organization (2)
• Management tasks (not limited to these)
– Monitoring the network for failures
– Diagnosing failures and communication outages
– Planning and carrying out repairs
– Provisioning new services and adding/removing
users
The Management Support
Organization: (3)
• Organization structure
– Network planning - analyzing network usage and traffic
patterns and planning network buildout and service rollout
– Network operation - keeping the network running and
monitoring the network failures
– Network administration – Deploying the network and
services on it
– Customer (user) management -Interacting with the
customers
The Management Support
Organization: (4)
• Administrator Operations
– Establishment of process and operational
policies, documentation of operational
procedures
• Help management of the network consistent and
efficient and facilitates meeting a consistently high
standard of operations
– Collection of audit trails
• Automatically logging the activities of operations
• make it easier to reproduce what happened and
recover from situation in which human error
The Management Support
Organization: (5)
– Network documentation
• Must be accurate and up-to-date
• Important for network planning and software upgrades
– Reliable backup and restore procedures
• Bring network back to live again in case of disaster and
emergencies
– Security emphasis
• Networks potentially most vulnerable from the inside
• Limit the damage that can cause by one person