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 = (internet) OID = (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) Connecting a craft terminal to a managed device and use CLI to configure and troubleshoot the network device Simple Management

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