T305: Digital Communications

T305: DIGITAL COMMUNICATIONS

Arab Open University-Lebanon Tutorial 8 1

T305: Digital Communications

Block II – Network Management


2Arab Open University-Lebanon

Tutorial 8

Introduction:

basic aim is to discuss Network Management

The various topics covered:Topic 1: Principles Of Network Management Topic 2: Managing SDH Networks Topic 3: Functional Architecture Topic 4: Management Functions And Layers



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Topic 1: Principles Of Network Management

Telecommunications management network (TMN) :

provides a framework for telecommunications management.

Management of a telecommunication network facilitates a number of changes in the way telecommunication operators can view their telecommunication resource.



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Example: management enables:• remote operation of equipment, which speeds up many day-to-day activities involved in providing and maintaining services,

• collection of information which helps faults to be dealt with proactively (before a complete failure) rather that reactively (after the event),

• easier interworking of equipment from different manufacturers,

• a view of information in terms that abstract away from the physical detail.




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The management view (cont.)The TMN:

do not set out to establish a prescriptive and detailed way of physically implementing network management; it provides a framework:

for the architecture of such a network, principles for organizing the information model, and definitions of managed object classes.




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The managing and managed network:

A telecommunication network :built up using SDH network elements. SDH network:

The top layer contains four fully meshed digital cross-connects (DXC). The middle layer contains two separate sub-networks joined together in a ring configuration by using cross-connects and joined together in a linear arrangement. The bottom layer is made up from three add/drop (ADM) multiplex rings.




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The managing and managed network:

The managed network: Telecommunication SDH network




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The managing and managed network (cont.)The telecommunications management network (TMN) is separated from the telecommunication network.

Fig. Telecommunications management network




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The managing and managed network (cont.)The two networks are connected together? For the TMN to be able to manage the telecommunication network it must have access to information contained within each network element it manages.

Managing the multiplexer telecommunication network




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The managing and managed network (cont.)This information is accessed through an agent, which resides in the network element and views each network element as a set of managed objects. Not all elements in the telecommunication network have agents, because some are only managed via other elements,


Fig. Manager and ADM



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The managing and managed network (cont.)The ADM is part of the telecommunication network; its function (in this case) is to drop a VC-12 from one STM-1 path on to another.

Add/drop Multiplexer.


VC-12 comes in on port 1 and exits on port 4.



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The managing and managed network (cont.)the ADM handles

all the timing extraction, pointer decoding and framing associated with multiplexing and all the coding functions associated with receiving and transmitting to line.

Fig. The relationship between the ADM and the manager

In a TMN the manager is part of a computer program and not a person.




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The managing and managed network:The manager controls the operation of the ADM via an agent. The manager can send operations to the agent, and the ADM can make requests of the manager through the agent. Example: If a VC-12 is to be dropped at the ADM, the manager will command the ADM to make the necessary connections, and the ADM will make the connection.


the agent acts as converting the ‘object’ language of the TMN into signals that can be understood by the multiplexer.



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Introduction:





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Topic 2: Managing SDH Networks Self-healing ring

Self-healing ring



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Topic 2: Managing SDH Networks (cont.) Ring management

In a real network a sub-network could be used to connect a group of local towns.

Fig. ADM ring.

to the wider telecommunication

Local access to the ring will be provided using add/drop principles at each node.

communication paths between each of the five nodes



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Topic 2: Managing SDH Networks (cont.)Ring management (cont.)

In management terms all the stages that are necessary in deciding where, when and how a ring should be installed can be classed as planning process.planning process: where, when and how a ring should be installed



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SDH equipment: possible to configure an ADM to provide interfaces for the range of containers that can be supported by SDH.Need for keeping precise records of how each ADM is configured. In management such records are called configuration information.



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Topic 2: Managing SDH Networks (cont.)

Ring management (cont.)same ADM ring with a configuration record held at each node.

This record-keeping arrangement is not one that is envisaged for SDH

configuration records within the ring need to be managed with a single view

Fig. Configuration records

each node has separate configuration records



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two alternative ways of connecting the network manager to each of the ADMs

Fig. Alternative data channel connections

an embedded data channel (DCC)

dedicated data network: independent of the managed network



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Topic 2: Managing SDH Networks (cont.)

Ring management (cont.)The ring manager has the capability to

look at all of the configuration tables use this information to determine where spare capacity exists in the network.

It can then set up new paths in the network by sending switching instructions to initiate add/drop or cross connect actions: this is part of the configuration management process



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Maintenance actions include: remote interrogation of the multiplexers either side of the fibre break and dispatching technicians to carry out on-site repairs.

•Maintenance is another example of a management action which is often incorporated in the performance management process.



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Introduction:





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Topic 3: Functional Architecture

Management networks In TMN:

Element: an item of telecommunication equipment

Network elements (NE): elements that are managed by the TMN



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Topic 3: Functional Architecture (cont.) Management networks (cont.)

NE: marks the boundary between the telecommunication network and the management network, between what is managed and what is doing the management.

Fig. Boundary between the TMN and the telecommunication network.

The boundary



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Topic 3: Functional Architecture (cont.) Management networks (cont.)

The aim of the TMN: provide a definition of how management information is organized.

TMN is an open architecture:Designed to allow elements from different manufacturers to be connected to the same management systemand management systems to be interconnected with other management systems.



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Topic 3: Functional Architecture (cont.)

Functional blocks:

Functional blocks provide a general architecture for the transport of management data within the TMN

so allowing it to perform the management functions.

The functional architecture is defined in terms of functional blocks.

Functional blocks separate out the functions that are necessary for the management network to communicate with the telecommunication network.



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Topic 3: Functional Architecture (cont.) Functional blocks (cont.)

Fig. Functions in an SDH ring.

the network element function (NEF):

implemented in one of the add/drop multiplexers in the ring

The minimum functions necessary to manage a simple network: •the workstation function (WSF):

provides a graphical user interface (GUI) to the operator.

•the operations system function (OSF):

resides in software in a computer



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TMN functional architecture: Two separate management

networks

InterconnectionA TMN functional

block

associated reference points



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TMN functional architecture: Two separate management

networks

InterconnectionA TMN functional

block

associated reference points

Q adaptor function

Mediation function (MF) blocks



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The (OSF) and the (MF) blocks: are wholly within the boundary of the TMN. The (WSF), (NEF) and (QAF) blocks all sit on the boundary of the TMN and the telecommunication network.



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Topic 3: Functional Architecture (cont.) Network element function (NEF) block

The NEF block: provides a home within the telecommunication network for the agent The agent will manage the network element. NEF:

provides activities to the TMN in a format defined by the information model and communicates operations from the manager to the network element.

NEF block activities: switching, alarm notification and performance The NEF effectively provides the communication boundary between the management and telecommunication networks.



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Topic 3: Functional Architecture (cont.) Workstation function (WSF) block

The WSF block: will convert TMN information into a format that can be easily understood by the user – perhaps a familiar windows format, for example. In the opposite direction, it will convert user input into a form usable by the TMN.

The (WSF) sits across the TMN boundarythe detail of exactly how information is presented to a user can be separated from the content of the information to be presented,it is left to individual operators to implement their user interface.



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Topic 3: Functional Architecture (cont.) Q adaptor function (QAF) block

The QAF block is used to translate proprietary information into a TMN format.

Operations system function (OSF) block The OSF block processes the information collected through the other blocks.



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Topic 3: Functional Architecture (cont.) Mediation function (MF) block

Data passing between an operations system function and network element function (or Q adaptor function) may need to be mediated or changed in some way which does not alter the information contained. The MF block carries out mediation functions that include adaptation, filtering and storage.

Reference points Reference points define the boundary between management function blocks and functions outside the TMN. It is at the reference points that the information passing between two blocks can be defined.



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Topic 3: Functional Architecture (cont.) Physical architecture of the TMN:

follows very closely the organization of the functional architecture. equivalent physical blocks can be found for each of the functional blocks each of the reference points is replaced with an interface.

TMN physical Architecture.

Data Communication Network

Interfaces



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Topic 3: Functional Architecture (cont.) Physical architecture of the TMN :

TMN physical Architecture.

Data Communication Network

Interfaces

•The definition of interfaces and the DCN enable details of how data is transferred within the TMN to be defined.



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Introduction:





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Topic 4: Management Functions And Layers Management functions:

The management domain/ management Functions.

Main components of the functional architecture

Vertical slices

The vertical separation of management functions represents the idea that each manager is responsible for all the activities that relate to its function, at any level of abstraction



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Topic 4: Management Functions And Layers Management functions:

The management domain/ management Functions.

1.Balance demand and resource

2. Receive specific requests for service•Translate requests then initiate actions

3. monitor network elements to detect alarms and other performance indicators defined in the information model.

4. To guarantee the integrity of data.

5. collects data for charging and billing.

Collected data: time of day and utilized bandwidth



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Topic 4: Management Functions And Layers Management layers

The ITU standards have identified four layers the management layers cut across the operations system function and the network element function. The important thing to note is that the layers divide the management domain horizontally.

Functional management layers

May/may not process some data before passing it.

Ex: major alarms

Managing more than one NE.

Actions affecting a group of elements



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May/may not process some data before passing it.

Ex: major alarms

Managing more than one NE.

Actions affecting a group of elements

•Provision of services.

•quality of service and service contracts.



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BML: takes a network-wide and strategic view meeting the business goals Strategic goals:

maximizing utilization, meeting performance targets, minimizing the costs of running the network, and efficiently managing the interconnection with other managed networks



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Topic 4: Management Functions And Layers Management layers (cont.)

the vertical and horizontal separations meshed together in a matrix to provide management services

Management servicesperformance management is handled at the service and network management layers

A dot indicates that an aspect of that management function is handled at that layer



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Topic 4: Management Functions And Layers Management layers (cont.)

The object of dividing management services into two different dimensions is to help organize the TMN by breaking down the problem – or problem space as it is sometimes called – into manageable chunks.

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