ppke itk 2011/12 tanév Őszi félév infocomm networks’ planning traffic aspects information...

PPKE ITK

2011/12tanév

ŐsziFélév

Infocomm networks’ planningtraffic aspects

Informationhttp://digitus.itk.ppke.hu/~gosztony/

1. TTE all around

(Arc de Triomphe, Paris)

.

1 - 1

What is TTE ?

(TTE – Teletraffic Engineering)

Is it required at all ?

2Infocomm networks' planning - traffic aspects - 2011. 09. 14.

.

Teletraffic theory is defined as the application of probability theory to the solution of problems concerning planning, performance evaluation, operation, and maintenance of telecommunication systems. More generally, teletraffic theory can be viewed as a discipline of planning where the tools (stochastic processes, queueing theory and numerical simulation) are taken from the disciplines of operations research.

TTE - in general

V.B. Iversen


.

Features of traffic handling capacity are required for:• a tervezéshez, (planning)• rendszerek teljesítményének értékeléséhez

(performance evaluation),• az üzemeltetéshez (operation) és • karbantartáshoz (maintenance)

Questions:• traffic: what is it and how large is it ?• what are traffic characteristics ?• how can traffic and its’characteristics be

measured?• ….. and calculated?

Basics 1. – the task


.

Teletraffic • data communication & telecommunication &

media infocommunication traffic

Tasks • Measurement of traffic size and characteristics• Description of traffic by mathematical models• Quality of service versus system details• Service quality monitoring• Planning of investments (short and long term)• Handling emergency situations

Basics 2. – details of the task


.

Human factor• stochastic and unpredictable

Reliability• failures: a stochastic

process Strategy

• computer: operating system• telecommunications: stored program control

Basics 3 – system details


.

Assumption of arrival processand holding time independence(basic case)

Subscriber beaviour modelling (eg. call repetition)

Basics 4. – the traffic

• measuring real systems• modelling, • iteration,


„Holding time” – what is it??

.

Both mathematical and simulation models• have to describe reality reliably• have to offer methods for

continuous checking, determination of parameters involved,

• have to be applicable in practice

Mathematical models might be easier applied, but very often there is no time for their elaboration.

Simulation models are trustworthy only if based on detailed measurement background.

Basics 5 - modelling


.

Convergence

Telecom Industry

mobility

main frames

desk top computingPC

PC-LANInternet

electronicpublishing andentertainment

Computer Industry

Media Industry

InfocomIndustry

Trends 1. - Convergence

Takács Gy.: Infocomm Systems_2010


.

Statements• The winner is: bit transport• We are in the age of practically

infinite bandwidth• We are in the age of the practically

free bandwidth („too cheap to meter”)• No distance limits within the globe• These facts together can lead to

revolution in the field of infocommunications

Trends 2. – Demands -1



.


“Network levelsat peak use timescan be as much astwenty-five timeshigher than duringlow-use periods.”

Anticipating the Bandwidth BottleneckMeeting Future Bandwidth DemandsMotorola, 2009. 01.

Traffic demand of USA households


.


Anticipating the Bandwidth BottleneckMeeting Future Bandwidth DemandsMotorola, 2009. 01.

“Network levelsat peak use timescan be as much astwenty-five timeshigher than duringlow-use periods.”


.

Trends 2. – Demands - 4

Source: Cisco VNI Hyperconnectivity and the Approaching Zettabyte Era, 2010. 06. 02.


Exabyte: 1018 byteZetabyte: 1021 byte

CAGR =compound annual growth rate

.

Trends 2. – Demands - 5


CAGR: Compound Annual Growth Rate Exabyte: 1018 byteZetabyte: 1021 byte

.

Trends 2. – Demands – 5a

Source: Cisco Visual Networking Index: Forecast and Methodology, 2008–2013, (2009.06.)

PB = petabyte(1015 byte)



.

Trends 2. – Demands – 5b

Source: Cisco Visual Networking Index: Forecast and Methodology, 2010–2015 (2011.06.)

PB = petabyte(1015 byte)



Compare5a and 5b

Saturation or

crisis ??

.

Trends 2. – Demands – 5c

Source: Cisco VNI Forecast and Methodology, 2010–2015 (2011.06.)


CAGR: Compound Annual Growth Rate

Petabyte: 1015 byteExabyte: 1018 byteZetabyte: 1021 byte

.

Consequence No 3 (infinite and free bandwidth supposed !)

Completely different user behaviour New ratio of :

• computing • downloading • storing!


Trends 3. – Attitude


.

Today’s SolutionsServices

Access, Transport & Switching Networks

CA

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MN

PS

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Connectivity

Future Solutions

Trends 4. – Network convergence



.

Trends 5.–Access network technologiesData Rate

Mobility10 kb/s

100 Mb/s

10 Mb/s

1 Mb/s

100 kb/s

Low MobilityPortableFixed High Mobility

P-P

Mic

row

. Rad

io

SH

DS

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GSM: 900 MHz, 1800 MHzGPRS: 900 MHz, 1800 MHzIS

DN

1 Gb/s

10 Gb/s

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DM

, ITU

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Sípos et al. PKI Nap 2004.


.

L2 (Ethernet) Aggregation

IP/ MPLS Network

Softswitch, contolls

Wired Wireless

Application servers

Man

ag

em

en

tApplication layer

Control layer

Transport layer

Access Network

GW GW


Trends 6. – NGN

MPLS-Multi Protocol Label SwitchingGW - Gateway


.

Where is TTE required ? We need TTE (Teletraffic Engineering) in dealing with.:

• backbone- and access networks,• circuit and packet switching arrangements,• fixed and mobile networks,• the evaluation of transmission systems,• time, space, etc. switches• different signalling systems, • fixed PSTN, IP, ADSL networks,• GSM networks and their traffic handling processes,• in-door systems,• satellite systems• VoIP and IMS (IP Multimedia Subsystem),• private networks,• NGN (New Generation Networks)

and all systems in which one can find bit-flows,...


.

Basics of network components

Backbone networks: long distances, high traffic, interconnection of nodes, transport bits of any services.

Access networks: local distances, interconnection of terminals and local nodes

Network planning: optimal selection of positions of nodes, dimensioning of node traffic handling capacities, dimensioning of link capacities, selecting technologies.

Takács Gy.:KomRendsz_2008

.. in all kind of networks


.

.. circuit and packet switching..



MPLS

.

Comparisonof wireline and wireless systems

.. fixed and mobile networks ..



.

Multiplexingprinciples

To reduce transmission costs To utilize higher bandwidth „Framing” and „packing” of

information TDM -- Time Division Multiplexing FDM -- Frequency Division

Multiplexing CDMA -- Code Division Multiple

Access WDM -- Wavelength Division

Multiplexing Mixed

..evaluation of transmission systems..



.

Time and space switches

.. time and space switches..



.

Connectionless transport:Destination address in the headerPath selection in the nodesDifferent packets have different delayThe order of received packets has no guarantee

Connection oriented transfer phases:Connection setup(setup packet with complete address, Logical Channel Number stored in each node.Data transmission (only LCN in the header).Release

.. different types of switching ..



.

Principles of Common Channel Signalling CCS

.. signalling ..



.

Signalling for distributed supplementary services

.. signalling ..



.

Signalling in

packet switched networks

.. signalling ..



.

Earlier telephone network structure of T-COM (MATÁV)

Secondary exchange

Primary exchange

Backbone network

Localexchange

Subscriber

Accessnetwork

Interexchangenetwork

.. fixed networks ..


Takács Gy.: Infocomm Systems 2010

.

KTV elérés

KTV elérés

Gigabit routert

maghálózat

GE

Dial-up

ATM connectivity

NB elérésEdge

ADSL

Edge

198 150ADSL felhasználó

12 523KTV felhasználó

11 487 dial-up port

1 366 1 260

Budapest

Dial-upATM

connectivity

ADSL

Edge


T-COM IP hálózat



T-COM IP network

.

What is ADSL?

Asymmetric Digital Subscriber Line, A modem technology, Convert existing twisted-pair telephone lines into

access paths for multimedia and high speed data communication,

Can transmit up to 6Mbps downstream, Can transmit up to 832 kbps upstream, Transform the existing PSTN network to a

powerful system capable of bringing multimedia, full motion video to the subscriber’s home.




.

GSM network components

Authentication CenterVisitor Location RegisterHome Location RegisterEquipment Identity Register

Gateway MSC

Base Station ControllerBase Transceiver StationNetwork Management CenterOperation and Maintenance Center

Mobile Station

Mobile services Switching Center

.. GSM networks ..

Takács Gy.: Infocomm Systems2010


.

.. GSM networks ..


GSM - Wikipedia2010. 09. 03.

.

GSM Geographic Network Structure

CELL: area of radio coverage by one BS antenna system, assigned to specific number (Cell Global Identity)

Location Area (LA): Group of cells, the identity of LA stored in VLR

MSC Service Area: Group of LA-s belonging to one MSC

PLMN Service area: set of cells served by one network operator (e.g. PANNON)

GSM Service Area: geographic area in which a subscriber can gain access to a GSM network (e.g. Europe)


.. GSM networks ..


.

Idle key

terms

Registration: MS informs a network that it is attached

Roaming: MS moves around the network in idle mode

International Roaming: MS moves into a network which is not its home network

Location Updating: MS inform the network when enters in new LA

Locating: BSC function to suggest connection to another cell based on MS measurement reports

Paging: The network tries to contact an MS by broadcasting message containing MS identity

.. GSM traffic handling processes ..

Takács Gy.: Infocomm Systems2010


.

.. GSM traffic handling processes ..



BasicHandover

.

Indoor wirelessconnections

.. indoor systems ..



.

.. satellite systems ..


VSAT - Very Small Aperture Terminal


.

VoIP (Voice over Internet Protocol): Summary term for the transmission of voice, telefax and related services over a partly or entirely packet switched IP network.

VoIP network: false term, since there are only IP based networks and they might offer VoIP.

IP (Internet Protocol): Communication protocol of the public Internet and of other dedicated IP based packet switched networks.

.. VoIP ..

A VoIP és a szabályozásDr. Bartolits István, NHH Szakmai Fórum Budapest, 2004.


.

PBX

PSTNPSTN

PSTN

Transit server

IP based

network

Inte

rnat

ion

al

bac

bo

ne

net

wo

rk

Multimedia PC

Multimedia PC

Colourful world of VoIP...

.. VoIP ..

Bartolits:NHH Szakmai Fórum 2004.


International bacbone network

Transit server

Transitserver

.

.. VoIP..

Bartolits I.: IP alapú beszédátviteli szolgálatok – NHH 2008.11


.

.. VoIP ..

Bartolits I.: IP alapú beszédátviteli szolgálatok – NHH 2008.11

Situation in Hungary(proportions were bigger than the European average)


.

.. IMS ..IP

Mu

ltim

ed

ia S

ub

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mW

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edia

, 2

01

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http://en.wikipedia.org/wiki/File:Ims_overview.png

.

Common features of private networks

Internal numbering schemes, addressing system

Strictly regulated gateway function for interconnection to other (public) networks

The transmission part of networks might be leased line or own connection (radio)

The multiplexing, switching, management, authentication processes are private functions

Task oriented service quality parameters (reliability, usability, error rate, response time, redundancy, backup time …)

Separated frequency management („governmental” use)

.. private networks - 1



.

An example of private networks

Hungarnet -- for research and academic community in Hungary

Pázmány CU is one of the members

Governmental support Part of EU GEANT project The transmission part is set of

leased dark fibre connections The switching and operation

function in the hand of HUNGARNET

www.niif.hu www.hungarnet.hu

.. private networks -2


GEANT:Gigabit European Academic Networking Technology


http://www.niif.hu/

http://www.niif.hu/

http://www.niif.hu/

http://www.hungarnet.hu/

.

Backb

on

e n

etw

ork

top

olo

gy

(only

the w

ide b

andw

idth

Hungari

an c

ountr

y

connect

ions

are

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ed)


.. private networks -3

http://www.niif.hu/files/halozati_topologia_2009.jpg

. 50Infocomm networks' planning - traffic aspects - 2011. 09. 14.

.. private networks - 4GÉANT2The world-leading research andeducation network for Europe.

Planned Topology by the end of 2010

.

.. to realize NGN -1

Coincidence of infocomm trends and paradigm shift

BartolitsNGN és Szélessáv Fórum2007


.


.. to realize NGN - 2

Basic features of NGN according the definition by ITU

• general use of packet switching;

• multiservice, broadband, QoS capable transmission;

• separation of service functions from transport functions;

• unrestricted access to different service providers

• support for general user mobility in accessing different services0


.


.. to realize NGN -3

Economic driving force of NGN

OPEX: Operating ExpensesCAPEX: Capital Expenses


CAPEX cost of NGN migration

NGN networkHybrid networkConventional network

Present Transition Future

OPEX cost

OPEX cost

CAPEX cost of NGN components

.


.. to realize NGN - 4

Migration models:

Upgrade – TDM network with NGN/VoIP capabilitiesReplace – NGN instead of the TDM networkOverlay or island-like –TDM and NGN together

MG – Media Gateway (NGN TDM)SIP – Session Initiation Protocol


.


.. to realise NGN - 5


Application layer

Control layer

Transport layer

Access layer

.

Where is TTE required ? We need TTE (Teletraffic Engineering) in dealing with.:

• transit- and access networks,• circuit and packet switching arrangements,• fixed and mobile networks,• the evaluation of transmission systems,• time, space, etc. switches• different signalling systems, • fixed PSTN, IP, ADSL networks,• GSM networks and their traffic handling processes,• in-door systems,• satellite systems• VoIP and IMS (IP Multimedia Subsystem),• private networks,• NGN (New Generation Networks)

and all systems in which one can find bit-flows,...


.

Summary-1.

Performance phenomena are observed in any shared resource system, as illustrated in following examples:

Road traffic: many vehicles share common resources like a lane. a junction etc. and traffic jams may result in case of heavy traffic.

Similarly, traffic problems in railway or airline systems occur due to temporary shortage of resources.

Queueing delay in front of a counter (bank, ticket office ) due to temporary overload of the serving person.

Blocking of a connection in a (telecommunications) network due to a temporary occupation of all available transmission links.

Response time delays for world wide web access through the Internet.


.

All of the before mentioned examples have a common reason for performance degradation:

the stochastic (random) nature of service requests and the random nature of resource occupations.

The variable density of requests and the variable occupation of a common server are responsible for short term overloads which result in blocking of shared resources. Shared resources are simultaneously used by a huge number of users who interfere with each other when accessing common resources. Once a system is overloaded it may happen that resources are blocked and cannot be used effectively so that the system throughput can fall far below its theoretical capacity.

Summary - 2.


.

A typical example is a computer system with too many users activated: the sharing of common memory leads to ineffective execution of user processes as frequent data transfers in and out of memory cause excessive overhead. To improve the performance, proper operating strategies have to be deployed to protect the system from being overloaded.

Similar phenomena are known from telecommunication systems: In an overload situation calls are blocked causing repeated call attempts; each unsuccessful attempt introduces processor overhead and reduces the call handling capacity.

Summary - 3.


.

Summary – 4.

For a proper system design and operation traffic performance studies can be made to detect bottlenecks and to dimension critical system resources adequately.

Traffic performance studies rest on models of the real system representing all relevant details (resources. traffic load. operational functions). The model can be analyzed either analytically (queueing theory, teletrafflc theory) or experimentally by computer simulations.


.

1 - 2

QoS – Quality of Service

GoS – Grade of Service

(Traffic handling capability)


.

Introduction

• Traffic handling capacity (and related parameters) give us information about one aspect of the quality of service experienced by users.

• Quality of service is affected by many factors which are partly independent but, at the same time are interrelated.

• Quality of service may be handled theoretically from a system engineering view, however a practical approach by defining and comparing relevant parameters might have practical importance as well.


.

QoS – relationships – 1.

ITU-T Rec. E.800 (2008)Definition of Terms Related to Quality of Service: Schematic contributions to end to end QoS – Figure 1. enhanced.

End to End QoS

Terminal

Equipment

Access

Network

AccessNetwork

Core

Network

U

S

E

R

USER

USER

TerminalEquipment

TerminalEquipment

AccessNetwork

AccessNetwork

CoreNetwork

wirelesscableADSL

etc

wirelesscableADSL

etc

performancevariability

performancevariability

single or multi provider,technology

(digital multiplexing, IP, etc.),transmission media

(air, optical or metal cable),etc.


.

ITU-T Rec. E.800 (2008)Definition of Terms Related to Quality of Service:

To specify the end-to-end QoS it is necessary to state the

specified operating conditions in which a service, supported over a

connection (connectionless or connection oriented), takes place.

The QoS could also be altered for a given set of specified operating conditions by

environmental conditions such as

traffic and routing.


QoS – relationships – 2.

.

QoS – system-approach –1.

ITU-T Rec. E.800 (2008)Definition of Terms Related to Quality of Service: Figure 2. enhanced

Quality of Service

Network Performance

Non – Network Performance

bit error rate,latency

(response time),etc.

provision time,repair time,

range of tariffs,complaints resolution time,

etc.

System-approach


.

QoS – system-approach- 2

ITU-T Rec. E.800 (2008)

2101 Quality of Service (QoS)Totality of characteristics of a telecommunications service that bear on its ability to satisfy stated and implied needs of the user of the service.

2118 Network PerformanceThe ability of a network or network portion to provide the functions related to communications between users.

Note 1: Network performance applies to the Network Provider’s planning, development, operations and maintenance and is the detailed technical part of QoSO.

Note 2: Network performance parameters are meaningful to network providers and are quantifiable at the part of the network, which they apply.


.

QoS – aspects – 1

ITU-T Rec. G.1000 (2001)Communications quality of service: A framework and definitions – Enhanced Figure 2.

User = user of theservice

Provider = service provider


.

ITU-T Rec. E.800 (2008)

2102 QoS requirements of user/customer (QoSR)A statement of QoS requirements by a customer/user or segment/s of customer/user population with unique performance requirements or needs. Note : The customer/user needs may be expressed in descriptive terms (criteria)

listed in the order of priority, with preferred performance value for each criterion. The Service Provider then translates these into parameters and metrics pertinent to the service (see E 802).

2103 QoS offered/planned by service provider (QoSO)A statement of the level of quality planned and therefore offered to the customer by the service provider.

Note: Level of QoS the service provider plans to achieve (and therefore offers)

to the customer/user is expressed by target values (or range) for measures of parameters pertinent to a specified service.

2104 QoS delivered/achieved by provider (QoSD)A statement of the level of QoS achieved or delivered to the customer.

Note: Achieved or delivered QoS is expressed by metrics for the pertinent parameters for a service.

68


Infocomm networks' planning - traffic aspects - 2011. 09. 14.

.

ITU-T Rec. E.800 (2008)

2105 QoS experienced/ perceived by customer/user (QoSE)A statement expressing the level of quality that customers/users believe they

have experienced.

Note 1: The level of QoS experienced and/or perceived by the customer/user may be expressed by an opinion rating.

Note 2: QoSE has two main man components; quantitative and qualitative. Thequantitative component can be influenced by the complete end-to-end systemeffects (network infrastructure).

Note 3: The qualitative component can be influenced by user expectations,ambient conditions, psychological factors, application context etc.

Note 4: QoSE may also be described considered as QoSD received andinterpreted by a user with the pertinent qualitative factors influencing his/herperception of the service.



.

QoS/NP – random character

Quality of Service/Network Performance

measurableparameters

(unit, actual value)

measurement errors

users’views fluctuate

(MOS)

reliability,maintenance

operationapplicationdamages

trafficforecasting, planning,

routing, fluctuation

the result has a

randomcharacter

MOS=Mean Opinion Score


.

Network accessibilityThe probability that the user of a service after a request (to a network) receives the proceed-to-select signal within specified conditions.NOTE – The proceed-to-select signal is that signal inviting the user to select the desired destination.

Connection accessibilityThe probability that a connection can be established within specified tolerances and other given conditions following receipt by the exchange of a valid code.

Trafficability performance

The ability of an item to meet a traffic demand of a given size andother characteristics, under given internal conditions.

NOTE: Given internal conditions refer, for example, to any combination of faulty and not faulty sub-items.

QoS/NP – terms (selection)

ITU-T Rec. E.800 (2008)


.

QoS - NP relationship

Table 3.1 – Categorization of QoS and NP parameters

Quality of Service parameter Network Performance parameter

User oriented Network provider oriented

Service related attributes Network element and technology related attributes

Focus on user observable effects Focus on planning development (design), operations and maintenance

Observed at service access points for the users, independent of network process and events

Observed at network connection element boundaries, e.g. relating to protocol specific interface signals

ITU-T QOS Handbook – Ed. 2004. 05.


.

QoS measurements – T-Com/Invitel (1)

www.nhh.huPiacfelügyelet

T-Com

Invitel


New dataare not

available

.

QoS measurements – T-Com/Invitel (2)

www.nhh.hu Piacfelügyelet

T-Com

Invitel


New dataare not

available

.

QoS – agreement

ITU-T Rec. 801 (1996 10) – Framework for Service Quality Agreement

SQA =ServiceQualityAgreement

A szolgáltatásminőség annak a mértéke, hogy mennyire felel meg a szolgáltató által a felhasználónak nyújtott szolgáltatás az ügyfél és a szolgáltató között létrejött megállapodásnak. (Eurescom)


.

QoS – example NIIF/HBONEQuality of Service (QoS) [1] :- HBONE policy is the same as GEANT QoS policy [2]- We apply DiffServ [3] QoS technology in HBONE.- QoS configuration can only be found there where the link load reaches 50%- MPLS:

In case of MPLS the EXP bits transfer the DiffServ priorityThe EXP field is 3 bit longMatching to the EXP bit values with the help of class-map (external label)- Defined HBONE QoS classes:5: realtime traffic (VoIP + video conference)

The VoIP traffic is the more important one from the two. The bandwidth defined for the QoS class is the sum of the max. traffic of the VoIP and the video conference (x*E1 + 2Mbps), so they do not interfere with each other.

3: premium0: best effort© 1986-2009 National Information Infrastructure Development Institute

Source URL (retrieved on 2009-02-16 17:07): http://www.niif.hu/node/129[1] http://en.wikipedia.org/wiki/Quality_of_service[2] http://www.geant2.net/server/show/nav.813[3] http://en.wikipedia.org/wiki/Differentiated_services

76

??


http://en.wikipedia.org/wiki/Quality_of_service



http://www.geant2.net/server/show/nav.813




http://en.wikipedia.org/wiki/Differentiated_services

http://www.niif.hu/node/129

.

Service Level Agreement -1.

E.860_F4-1

Service Level Agreement

Service Description QoS Agreement

Legal Issues Billing

...

USERPROVIDER

Figure 4-1/E.860 – One stop responsibility and Service Level Agreement


.

Figure 4-2/E.860 – Application of the one stop responsibility concept



.

Figure 5-5/E.860 – QoS parameter levels in Timeline Model



.

Figure 6-1/E.860 – Association of entities which are involved in realizationof the End-to-End QoS

Service Level Agreement - 4.


.

1 - 3

Service Quality

related activity in the

International Telecommunication Union(ITU)


.

International standardsorganisations

World- organisations ISO - International Standards Organization IEC - International Electrotechnical Commission ITU - International Telecommunication Union

European organisations CEN - European Committee for Standardization CENELEC - European Committee for

Electrotechnical Standardization ETSI - European Telecommunications Standards

Institute


.

2. Operational aspects of service provision and telecommunications management,

3. Tariff and accounting principles including related telecommunication economic and policy issues,

5. Protection against electromagnetic environment effects, 9. Television and sound transmission and integrated

broadband cable networks,

ITU-T –Study Groups

11. Signalling requirements, protocols and test specifications,12. Performance, QoS and QoE,13. Future networks including mobile and NGN,15. Optical transport networks and access network

infrastructures, 16. Multimedia coding, systems and applications,17. Security,

(Period 2009-2012)


.

TTE – ITU-T framework

ITU–T Rec. E.490.1 (2003. 01): Overview of Recommendations on traffic engineering.


.

Reminder – TTE in general

Teletraffic theory is defined as the application of probability theory to the solution of problems concerning planning, performance evaluation, operation, and maintenance of telecommunication systems. More generally, teletraffic theory can be viewed as a discipline of planning where the tools (stochastic processes, queueing theory and numerical simulation) are taken from the disciplines of operations research.


.

The cost of communication systems depends on:• the number of users• the amount of traffic

Systems have to be planned with the aim that fluctuation of users’ demand should not cause inconvenience (service degradation !).

Infocommunication systems corresponding to traffic demands is the goal of TTE

TTE – Teletraffic Engineering


.

GoS 1. – decisions at start

Grade of Service – GoS

Services

Quality of service(components !)

Network infrastructure

Information transfer mode

Market presence?

Costs ?

Transport networkReliabilityTraffic routing


.

QoS/NP – Reminder

ITU-T Rec. E.800 (2008/09)

2101 Quality of Service (QoS)Totality of characteristics of a telecommunications service that bear on its ability to satisfy stated and implied needs of the user of the service.

2118 Network PerformanceThe ability of a network or network portion to provide the functions related to communications between users.

Note 1: Network performance applies to the Network Provider’s planning, development, operations and maintenance and is the detailed technical part of QoSO.Note 2: Network performance parameters are meaningful to network providers and are quantifiable at the part of the network, which they apply.

Trafficability performanceThe ability of an item to meet a traffic demand of a given size and other characteristics, under given internal conditions.

NOTE: Given internal conditions refer, for example, to any combination of faulty and not faulty sub-items.


.

A number of traffic engineering variables used to provide a measure of adequacy of a group of resources under specified conditions. These grades of service variables may be probability of loss, dial tone delay, etc.

GoS 2. – Definition

Parameters – GoS parameters selection e.g. probability of delay

Prescribed parameter value – GoS standards standard value

Achieved parameter value – GoS results achieved value

ITU-T Rec. E.600 (1993/03)


.

1 - 4

Infocommunication traffic

a closer view

Concepts, characteristics, points of measurement


.

Traffic 1. – Terms

Definition: The instantaneous traffic intensity in a pool of resources is the number of busy resources at a given instant of time.

The pool of resources may be a group of servers, e.g. trunk lines, registers, buffers.

Traffic intensity(traffic per time unit)

dt. tn · T

1 (T) Y

T

0

n(t) = number of busy devices at moment t

Unit: erlang (E) – after Erlang, a Danish mathematician Dimensionless


.

Traffic carried

Definition: The traffic served by a pool of resources.The average traffic intensity in practice

Traffic volume

Definition:Traffic volume is equivalent to the sum of the holding times in the given time interval.

Unit: erlanghour (Eh)

Lost/rejected trafficDefinition:The difference between offered traffic and

carried traffic



. 93Infocomm networks' planning - traffic aspects - 2011. 09. 14.


.

Offered trafficDefinition: The traffic that would be carried by an

infinitely large pool of resources

sA .

l = call intensity, calls/demands offered by unit times = average service/holding time

Can not be measured !!

ii

N

ii dsA ..

0

In the case of N traffic types, each of which seizes several channels:

si = average service time of traffic type i

di = number of occupied channels by the calls/demands of traffic type i



.

10 s.

Utilisation

arrival intensity of jobs speed of data transfer (e.g. job units/sec)s the unit of the job (e.g.: bit, byte, packet, frame)

10



.

10 Busy hour

Different definitions might exist

Time consistent busy hour, (TCBH): those 60 minutes (determined with an accuracy of 15 minutes) which during a long period on the average has the highest traffic.

It may happen that the traffic during the busiest hour is larger than the time consistent busy hour, but on the average over several days, the TCBH traffic will be the largest.

We also distinguish between busy hour for the total telecommunication system, an exchange, and for a single group of servers, e.g. a trunk group. In practice, for measurements of traffic, dimensioning, and other aspects it is an advantage to have a predetermined well–defined busy hour.



The TCBH concept above reflects the experience related to traditional voice telephone traffic. For other traffic types the length of the busy period might be different.

.

TTE – ITU-T framework

ITU–T Rec. E.490.1 (2003. 01): Overview of Recommendations on traffic engineering.


.

Traffic measurement

ITU-T Rec. E. 490 (1992.06)


.

Telephone traffic characteristics – 1.

Konkoly Lászlóné: Forgalomtechnika – OKTIG 1998

Forgalom[erlang]

Idő (óra)

forgalmas órai forgalom

forgalmas óra

4. ábra: A napi forgalom ingadozása

1 0 11 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 37 8 9

99

Traffic fluctuation during the day

Busy hour


.


Forgalom[erlang]

Napok

5. ábra: A heti forgalom ingadozása(Naponta a 10 - 11 óra közötti forgalom )

H K S z C s P S z V

100



Traffic fluctuation during the week

.


F o rg a lo m[e rlan g ]

Hónapok

6. ábra: Az éves forgalom ingadozása(Havi átlagok)

Jan. Febr. Á pr.M árc . M áj. Jún. Júl. A ug. S zept. O kt. Nov. Dec.

101

Traffic fluctuation during the year



.


Forgalom[erlang]

Idő

7. ábra: Forgalom mennyiség

1 0 11 1 27 8 9

102


Traffic volume


.

Figure 2.3: The mean number of calls per minute to a switching centre taken as an average for periods of 15 minutes during 10 working days (Monday – Friday). At the time of the measurements there were no reduced rates outside working hours (Iversen, 1973 [36]).

103



.

104



.

Figure 2.5: Number of calls per 24 hours to a switching centre (left scale). The number of calls during busy hour is shown for comparison at the right scale. We notice that the 24– hour traffic is approximately 8 times the busy hour traffic. This factor is called the traffic concentration (Iversen, 1973 [36]).



.

Figure 2.9: Frequency function for holding times of trunks in a local switching centre.



.

Hívottválaszánakideje (sec)

107



.

108

Internet traffic characteristics – 1.


.

1400014000



.

1200



.

Portugália, 2002

111



.

Portugália, 2002

DNS = Domain Name Server/ServiceHTTP = Hyper Text Transfer Protocol HTTPS = Hyper Text Transfer Protocol Secure sockets POP3 = Post Office Protocol version 3 SMTP = Simple Mail Transfer Protocol (internet email)

TCP = Transmission Control ProtocolUDP = User Datagram Protocol

Distribution of services



.

Portugália, 2002

Empirical distribution of the IP packet size

113



.

Portugália, 2002

Bandwidth consumption over 4 days



.

Portugália, 2002

115



.

Portugália, 2002

Empirical distribution of the size dependent number of packet retransmissions

116



.

Portugália, 2002

Empirical distributionof the number of retransmissions

117



.

Portugália, 2002

Empirical distributionof the maximal timefor a successful packettransmission

118



.

Hárs Péter( PPKE-ITK)FTTH Optikai hálózat Bólyban. 2008.

dailyweekly datayearly

Total traffic of the FTTH Triple Play system of Bóly Measured at the input of BIX.(BIX = Budapest Internet Exchange)

119



.

120

Giga !



IPv4Traffic fluctuation during the day

.

121

Giga !



IPv4Traffic fluctuation during the week

.

122

Mega !



IPv6Traffic fluctuation during the day

.

123

Mega !

Internet traffic characteristics – 16a.


IPv6Traffic fluctuation during the week2011. 08. 29

.

124

Compare 16a. with 16b.

Internet traffic characteristics – 16b.

IPv6Traffic fluctuation during the week2010. 08. 28.


.

125

http://www.internetworldstats.com/stats.htm


Internet traffic characteristics – 17a.

.

126


Internet traffic characteristics – 17b.


.

127



Internet traffic characteristics – 17c.

.

Reference connections – 1.


.

CPN – Customer Premises Network

ITU-T Rec. E.651 (2000/03) Reference connections for traffic engineering of IP access networks

End-to-end all-IP connections

129



.

CPN – Customer Premises Network

IP and PSTN/ISDN interworking

ITU-T Rec. E.651 (2000/03) Reference connections for traffic engineering of IP access networks

130



.

ITU-T Rec. E.470 (2005/02) - Operational considerations for QoS of voiceover IP-based networks with PSTN-IP-PSTN architecture

131



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