Active Network Management

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Active Network Management

• Rajendra Singh
• Graduate student
• Dept. of Computer Sc..
• University of Manitoba, Canada

2
Current Network Management

• Network elements are instrumented to support
• monitoring of element performance
• configuring elements operational parameters
• reporting operational events
• MIB maintains the instrumentation directory
• Agent allows the NMS to access and manipulate MIB
  var. via SNMP

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Limitations of present Management

• When an active element is loaded into an element,
  the instrumentation and MIB component must also
  be loaded and integrated with the element SW
• Similar MIB component must be loaded in the NMS
• Management application tools must be programmed
  to process MIB data associated with active
  element
• Dynamic changes in the element mgmt. SW and NMS
  must be synchronized with the changes of active
  network
• MIB at element and NMS must be changed , if any
  change is there in MIB var.
• Active element must adapt to and control the
  network behavior(performance and configuration)

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Requirements for managing Active Networks

• Dynamically composable management
• ANet management Should provide means for dynamic
  composition of management modules, to adapt
  dynamic changes in the active elements of the
  network
• It should support adaptation of node
  instrumentation and mgmt SW
• Coordinate changes of mgmt. SW at nodes and NMS
  with changes in active element configuration
• It should provide mechanisms for EEs to export
  their interfaces to Node Manager, so that other
  EEs can use these interfaces for their
  operations

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Requirements

• Backward Compatibility with SNMP
• ANet should support SNMP mgmt. Framework
• SNMP should be incorporated with active elements
  instrumentation for configuration and monitoring
• It should provide appropriate MIB extensions to
  access this instrumentation via SNMP

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...Requirements

• Application controlled Management
• Active applications should be provided means to
  monitor and control network configuration and
  behavior
• Should provide means to obtain network topology
  and resource availability info
• monitor network performance parameters
• monitor exceptional network performance events

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...Requirements

• Automation of Configuration Management. It should
  provide
• means to facilitate automated configuration
  changes
• provide means to undo configuration changes,
  whether it is from AA or SW
• provide means to assure configuration consistency
  through changes

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...Requirements

• Automation of Problem Management
• Secure Management
• Generation of Active element management Data and
  Instrumentation
• ANet should provide means to derive management
  instrumentation and data models from the
  structure of EE and/or AA code

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ANM Architecture

• Network Management Station(NMS)
• Active Node Manager
• Execution Environment(EE)
• Active application(AA)
• Node OS API
• Instrumentation
• Communication/Processing HW/SW

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NMS
Active App
EE
Anet Node Mgr
OS
Instrumentation
Communication/Processing HW/SW
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...Architecture

• Node Manager Interacts with----
• Local node instrumentation via Node OS API.
  (performance data, configuration data,
  operational events)
• EE to support
• Management of EE configuration, problems, and
  performance
• adaptation of dynamic changes in active
  applications
• management of node configuration objects by other
  EEs and AAs

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...Architecture

• It exposes the APIs to EE (so that AA could
  adapt and control network resources i.e., monitor
  performance and configure resources)
• NMS to support remote management functions and to
  adapt its SW to dynamic changes in the active
  applications

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...Architecture Node Manager

• Consists of SW to monitor, configure, analyze and
  control a node.
• It is actually divided in three layers---
• Instrumentation layer(provides adapters to
  support access to event and management data
  provided by various node components)
• Active MIB(provides access to this
  instrumentation)
• Data Modeling Layer
• it organizes the management data to enable
  manager applications to access and analyze data
  models of the network configuration and
  performance behavior
• it also handles synchronous data access by
  applications, as well as asynchronous event
  notifications.

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...Architecture ...Node Manager

• Consists of Local Manager SW(LMS) (responsible
  for managing specific node functions and
  components like EEs, AAs, etc.)
• Supports access mechanisms and protocols to
  interact with NMS(SNMP is used)
• Supports SNMP agents to access data and events of
  the instrumentation
• consists of an event manger that keeps track of
  all the events and reports it to the Node Manager
  and NMS.

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Automating the above design

• Common Management Framework(CMF)
• To support the Node Manager frame work
• A discovery mechanism to probe newly deployed
  EEs is adapted
• After deployment EEs respond to a predefined
  and universally agreed upon ANEP packet INIT
• To this INIT packet, EEs respond with an ANEP
  EXPORT packet
• The EXPORT packet contains information to be used
  for configuration and monitoring of the EE itself
  and the configuration of other related EEs

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...Automating CMF flexible runtime adaptation
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...Automating

• CMF (contd..)
• In general INIT/EXPORT mechanism can be seen as
  the bootstrap mechanism that allows an EE to
  integrate itself into the Node Manager
  infrastructure
• The NMS that deployed the service I.e., EE,
  queries the service by INIT packet, the service
  or EE responds to it by sending an EXPORT packet
• These EXPORT packets are processed by NMS for
  remote management
• I may also happen that EXPORT information may be
  forwarded to other entities in the Network
  framework like to the NM EE, which resides near
  the same node where the EE was deployed

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...Automating

• CMF (contd..)
• NMS could also TRIGGER NM EE to send an INIT
  packet to the EE which is newly deployed and
  hence avoiding the forwarding job
• The NMS EE when receives the EXPORT packet, it
  processes the packet and extends the local NM
  system to incorporate the newly deployed EE in
  its NM scope

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Backward compatibility with SNMP

• EE replies by the EXPORT packet
• SNMP agents are also dynamically deployed
• If a deployed service or EE wants to use SNMP,
  then it replies in its EXPORT packet with
  information encapsulated in the SNMP-specific
  MIME type
• The reply specifies
• The URL of the SNMP agent
• The associated MIB
• The access control information to be loaded with
  the service

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...Compatibility

• The NMS processes this EXPORT reply and it
  deploys and configure the SNMP system
• The EXPORT reply would also cause the management
  station(NMS) to either
• spawn an SNMP browser to access the deployed
  service or EE or
• update an existing SNMP management application
  with the new MIB

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Adaptation to Active Code

• Active elements are deployed dynamically which
  changes the contents of a Node
• Adaptation to these changes are done as follows
• The instrumentation layer or AMIB needs to
  incorporate components to configure monitor
  active elements
• These components should be updated with
  deployment or deletion of those active elements
• One way is that, the active elements may carry
  its MIB instrumentation and deploy it in Nodes as
  related elements
• Other way is that, create a uniform AMIB deploy
  it in independent manner
• The DML needs to be updated dynamically and bound
  dynamically to respective components at the
  instrumentation layer

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...Adaptation

• The LMS associated with a set of active elements
  will need to be updated dynamically to support
  configuration problem management of the
  respective active application
• How this runtime adaptation takes place?
• After deployment, an EE that subscribes to the
  CMF may be queried with the ANEP INIT command and
  that EE returns the EXPORT packet which contains
  instructions like
• new object to be added to the active MIB
• new abstraction function to be added to the DML
• new local manager to be loaded in to the Node
  Manager EE

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Instrumentation Layer AMIB

• New EEs or AAs are added to the node
• they EXPORT an instrumentation to be used to
  access their services or performance
• this information is exported to the AMIB
• AMIB automatically extends it
• AMIB is similar to SNMP MIB with two more
  features
• Each variable has a specific method calling
  convention associated to it. The instrumentation
  layer uses it to access each object
• Each variable also has some regulations for
• polling nadalities
• access restrictions
• synchronization requirements

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...AMIB

• AMIB contains some information about the object
  like
• Criticality - to what extent the value of the
  object is critical for the correct operation of
  the system
• Frequency of change - tells NM, how often the
  object is expected to change
• Accessibility - who can access or affect the
  object
• This information facilitate the runtime inclusion
  of the new object into the NM infrastructure

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Data Modeling Layer

• When EEs are deployed or new objects are added
  in the instrumentation layer, then the new
  modeling services are adapted
• These services provide access to higher level of
  abstraction rather than low level AMIB
• The functions that are contained in this layer
  provides access to the EEs in the node or the
  NM, or provides better functionality
• It organizes management data in a form that
  enables local remote applications to access
  analyze the network configuration performance

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...Data Modeling Layer

• It enables manager to configure and control
  network components and to monitor and correlate
  their behavior
• It contains configuration attributes of managed
  objects
• It contains the performance behavior attributes
  of managed objects
• It contains the relationship between the managed
  objects

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Local Manager Software(LMS)

• Local manager is responsible for managing node
  functions under local or/and remote control
• Local managers are also installed dynamically and
  implement distributed NM services
• These managers may access either the DML
  functions or the AMIB directly and are the basic
  building blocks of the Active NMS
• Node Manager manages the local HW, SW, etc it
  configures and monitors the performance of these
  resources and handles their operational prpoblems

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...LMS

• EE manager configures and monitors the
  performance of an EE. This includes configuring
  the EE, allocating resources to an EE, linking EE
  with VANs and monitoring the performance of an
  EE, monitoring active elements execution on top
  of an EE
• Active App Manager configures and monitors
  individual active applications

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What is SNMP

• SNMP is a protocol called as Simple Network
  Management Protocol, it used to exchange data
  about network activity. With SNMP the data
  travels between the managed device and the NMS,
  where users remotely manages the network. We can
  monitor a server or any element of the network in
  real time by using the SNMP protocol
• The managed devices could be anything that runs
  the SNMP that is any network element may be
  server, router, host, etc. anything.
• Managed devices like servers, routers, etc.
  contains an SNMP agent that gathers the
  information regarding the network activity of
  that device. This agent is called as Sub Agent.
• Master Agent is also an agent which exchanges the
  information between the subagent and NMS. This
  also runs on the same host machine as the
  subagent it talks to.

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...SNMP

• Every managed object is known as a variable
• The agent can access any variable or element and
  report to NMS
• All these managed objects are maintained in the
  MIB, which is a database that has a tree-like
  hierarchy
• The communication can be two way the manager
  asking the agent for a specific value or the
  agent telling the manager that something
  important happened
• the manager should be able to set variables in
  the agent in addition to reading variables from
  the agent.

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...SNMP Network management consists of three
pieces

• MIB - A Management Information Base (MIB) that
  specifies what variables the network elements
  maintain (the information that can be queried and
  set by the manager)
• SMI - A set of common structures and an
  identification scheme used to reference the
  variables in the MIB. This is called the
  Structure of Management Information (SMI)
• SNMP - The protocol between the manager and the
  element, called the Simple Network Management
  Protocol (SNMP) This details the format of the
  packets exchanged. Although a wide variety of
  transport protocols could be used, UDP is
  normally used with SNMP

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...SNMP

• Statements defined in SNMP
• get_request - fetches the
  value of var.
• get_next_request - fetches
  the next var.
• set_request - set the value of
  var.
• get_response - return the
  value of var.
• Trap - notify the mgr.

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...SNMP Communication
UDP is used
Get_request
Time out and transition is used
Get_response
Get_next_request
Get_response
Set_request
Get_response
Trap
SNMP agent
SNMP manager
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NMS
Network Elements
responds
Queries via SNMP
Reports
Sends result
Master agent
subagent
MIB
Sends query to subagent
Looks up in MIB
Communication is via SNMP
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• Thats it