qos issues in heterogeneous ip networks - aalto...2006-9-8 计算机科学与技术学院...

WendongWendong WANGWANGBroadband Network Research Center (BNRC)Broadband Network Research Center (BNRC)

State Key Laboratory of Networking and Switching TechnologyState Key Laboratory of Networking and Switching TechnologySchool of Computer Science & TechnologySchool of Computer Science & Technology

Beijing University of Posts and TelecommunicationsBeijing University of Posts and TelecommunicationsSeptember 2006September 2006

QoSQoS Issues Issues in Heterogeneous IP Networksin Heterogeneous IP Networks

Lecture 1 of 4: Lecture 1 of 4: QoSQoS concept, Standards and Architectureconcept, Standards and Architecture

2006-9-8计算机科学与技术学院计算机科学与技术学院

国家重点实验室国家重点实验室宽带网研究中心宽带网研究中心22王文东王文东

Contents OverviewContents OverviewCourse introductionQoS backgroundQoS ConceptQoS StandardsQoS ArchitectureQoS TechnologiesQoS issues in heterogeneous IP Networks



Course introduction



Goals of the Course Goals of the Course

Learn knowledge of QoS from classRead papers after class to know more QoS technologiesSelect one topic for intensive reading to know QoS in a specific area.Share your QoS topic with others and extend your QoS knowledge.



Course References Course References Books:

Zheng Wang, “Internet QoS: Architectures and Mechanisms for Quality of Service”, Morgan Kaufmann Publishers, 2001, ISBN:1-55860-608-4Kun II Park, “QoS In Packet Networks”, Springer, 2004, ISBN:0-387-23389-x

Papers:John Soldatos, Evangelos Vayias, George Kormentzas. ON THE BUILDING BLOCKS OF QUALITY OF SERVICE IN HETEROGENEOUS IP NETWORKS. IEEE Communication Surveys. Vol.7, No.1, 2005Sotiris I. Maniatis, Eugenia G. Nikolouzou, Iakovos S. Venieris, “End-to-end QoS specification issues in the converged all-IP wired and wireless environment”, IEEE Communications Magazine,vol.42, No.6, June, 2004……



Schedule of the Course Schedule of the Course QoS Concepts, Standards and Architectures

Aug. 8th 8:00-10:00 QoS technologies

Aug. 13th 16:00-18:00Aug. 15th 8:00-10:00

QoS issues in Heterogeneous IP NetworksAug. 20th 16:00-18:00

Presentations ( ? )



ProjectsProjectsA research paper on the topic of your choice related with QoSStages:

Topic selectLiterature searchPaper readingPaper writingTopic presentation (?)



Project requirementsProject requirementsContents

Technical Research or analysisTechnical survey or review

ReferencesRecent technical papers (3-5 years)Standards (ITU-T,IETF,ETSI,3GPP……)Technical white papers of some companies

ResultsPaper in 6-8 pages Presentation (?)



Project topics (1)Project topics (1)Core Network

QoS issues in Diffserv-aware MPLS/MPLS TEQoS issues in Premium IP networksQoS issues in Next Generation Network/Internet (NGN/NGI)QoS issues in IP Multimedia Subsystem (IMS)QoS signaling (ITU,IETF,ETSI, 3GPP)



Project topics (2)Project topics (2)Access networks

QoS issues in Wireless networksQoS issues in wireless LANQoS issues in WiMaxQoS issues in 2G/3G wireless networks (GSM/GPRS/WCDMA, CDMA)QoS issues in 4G wireless networksQoS issues in Ad-hoc and sensor networksQoS issues in Home Networks



Project topics (3)Project topics (3)Applications and Interworking

QoS issues in Mobile IPQoS issues in IP Telephony over Wireless/ Mobile networksQoS issues in interworking of different wireless networksQoS issues in P2P applicationsQoS issues in Services management systems



QoS background



Situation of current InternetSituation of current InternetCurrent Internet is a Best Effort network:IP Packets forwarding is in best effort modeNo guarantee for Packets loss and Packets Transfer Delay as well as Packet Delay VariationBetter performance when network resources are plentyWorse performance when network resources are congested



IP Packets in current InternetIP Packets in current Internet

2) IP packet is lost1) IP packet is delayed

Network Traffic Help

File Edit Locate View Help

1 2 3 4 5 6 70

100

200

300

400

500EDCBA

IP network



Some issues for Internet developmentSome issues for Internet development

BandwidthEndless bandwidth requirements for Internet applications

SecurityMore and more applications need Authentication and Authorization

Quality of ServiceMultimedia Services for different user’s requirement

AddressAlmost exhausted IPv4 address for mobile terminals

Management and chargingNetwork O&M requirements



IP network

Quality of ServiceQuality of ServiceServices: Telephone, Video conferences, Video on Demand, HTTP, EMAIL, FTP, VoIP,…..Quality: the general feeling of service usersE2E QoS is the key issue for service users, but network QoS is the basis for E2E QoS

Application

User

Server/Application

End-to-End QoS



Why we need Why we need QoSQoS

Service/Network performance

Service/Network Convergence

User/Service/Network diversities

Service/Network Operation & Maintenance



TCP Application: - Packet loss will cause the retransmission

-> Need more time to transfer files, images and web pages, …

-> Retransmission increase the network traffic and may cause congestionUDP Application: - For delay sensitive application -> unexpected packet

delay will cause packets invalidation - For loss sensitive application -> Introduce application

layer retransmission and reduce the application performance

QoSQoS effect for Internet Applicationseffect for Internet Applications

IPTCP UDP

Application



Problems of Best Effort InternetProblems of Best Effort Internet

Self-similar model of IP service shows that TCP Traffic has strong bursting characteristics. But Video and Voice services do not have.In Best Effort environment, QoS of integrated TCP and Voice as well as Video can only be guaranteed by bandwidth over-provisioning.In this case, normally the resources usage factor of network could only be 30%-40%

Voice

Video

Web, Ftp



How to provide How to provide QoSQoSResource over-provisioning

Massive bandwidth

Admission control and resource managementUser services restriction：only provide services with the QoS guarantee to those allowed users.User services preference：provide services to all users while keeping the QoS guarantee to the users who has services priority.



Some IP Some IP QoSQoS research resultsresearch results

Architectures, ModelsMechanisms, components, signallingsTest bed and field trail (Qbone, Internet2,…)Lots of Papers both on Conference and JournalsDozens of Standards from ITU-T, IETF, ETSI, 3GPP/3GPP2,……



Current Current QoSQoS research research QoS fundamentals

New Architectures and Signaling (GENI, IETF NSIS)New algorithms and mechanisms (Lots of papers)……

QoS applicationsQoS in wired networks/MPLS/MPLS TEQoS in wireless/mobile networksQoS in Ad-hoc/Sensor networksQoS in VoIPQoS in P2P networks……



QoS Concept



Standardization GroupsStandardization GroupsIETFITU-TETSI3GPP/3GPP2ATM Forum, MSF……



QoSQoS model and approachesmodel and approaches



IETF IETF QoSQoS definitiondefinition

IETF RFC2386

Quality-of-Service (QoS): A set of service requirements to be

met by the network while transporting a flow.



IETF IETF QoSQoS ParametersParametersNetwork connectivity

One way and two wayPacket Transfer Delay

One way delay & round-trip delayPackets Loss Rate

One way loss & round-trip lossPacket Delay VariationPacket reorderingLink bandwidth capacity……



ITUITU--T T QoSQoS definitiondefinition

ITU-T Recommendation E.800

Quality of Services: The collective effect of service

performance which determine the degree of satisfaction of a user of the service.



ITUITU--T Four Viewpoint of T Four Viewpoint of QoSQoSQoS requirements of customer: a statement of the level of quality required by the applications of customers of a service, which may be expressed non-technically.QoS offered by provider: a statement of the level of quality expected to be offered to the customer by the service provider.QoS achieved by provider: a statement of the level of the actual quality achieved and delivered to the customer.QoS perceived by customer: is a statement expressing the level of quality that customers believe they have experienced.



ITUITU--T NP Definition T NP Definition

ITU-T Recommendation E.800

Network Performance: The ability of a network or network portion to provide the functions related to communications between users.



ITUITU--T NP ParametersT NP ParametersIP Packet Transfer Delay (IPTD)

Node process delay＋Link transmission delay (one way)

E2E IP Packet Delay Variation (IPDV)IP Packet Error Ratio (IPER)IP Packet Loss Ratio (IPLR)percent IP service unavailability (PIU)percent IP service availability (PIA) ……



QoS Standards



MeasurableMeasurable parameters of IP parameters of IP QoSQoSServices availability

Network ConnectivityLatency

IP Packet Transfer DelayJitter

IP Packet Delay VariationPackets loss

IP Packet loss ratioThroughput

Available bandwidth



QoSQoS class definition in ITUclass definition in ITU--TTTable 1/Y.1541 – Provisional IP network QoS class definitions and

network performance objectives

QoS ClassesNetworkperformance

parameter

Nature of network performance objective Class 0 Class 1 Class 2 Class 3 Class 4 Class 5

Unspecified

IPTD Upper bound on the mean IPTD

100 ms 400 ms 100 ms 400 ms 1 s U

IPDV Upper bound on the 1 −10–3 quantile of IPTD minus the minimum IPTD

50 ms 50 ms U U U U

IPLR Upper bound on the packet loss probability

1 × 10–3 1 × 10–3 1 × 10–3 1 × 10–3 1 × 10–3 U

IPER Upper bound 1 × 10–4 U



Service Service QoSQoS requirementsrequirements

T1213050-02

0%

5%

Fax100 ms 1 s 10 s 100 sDelay

Conversationalvoice and video

Voice/videomessaging Streaming

audio/video

Command/control

(e.g. Telnet,Interactive games)

Transactions(e.g. E-commerce,

Web-browsing,E-mail access)

Messaging,Downloads

(e.g. FTP, still image)

Background(e.g. Usenet)

Packet Loss

Zeroloss

Figure 1/G.1010 – Mapping of user-centric QoS requirements



QoSQoS categories & services mappingcategories & services mapping

T1213060-02

FaxErrortolerant

Conversationalvoice and video

Voice/video messaging

Streaming audioand video

Errorintolerant

Command/control(e.g. Telnet,

interactive games)

Transactions(e.g. E-commerce,WWW browsing,

Email access)

Messaging,Downloads

(e.g. FTP, still image)

Background(e.g. Usenet)

Interactive(delay <<1 s)

Responsive(delay ~2 s)

Timely(delay ~10 s)

Non-critical(delay >>10 s)

Figure 2/G.1010 – Model for user-centric QoS categories



Guidance for IP Guidance for IP QoSQoS classes (Y.1541)classes (Y.1541)

QoSclass

Applications (examples) Node mechanisms

Network techniques

0 Real-time, jitter sensitive, high

interaction (VoIP)Constrained routing and distance

1 Real-time, jitter sensitive, interactive (VoIP).

Less constrained routing and distances

2 Transaction data, highly

interactive (Signalling)Constrained routing and distance

3 Transaction data, interactiveLess constrained routing and distances

4 Low loss (short transactions, bulk data, video streaming)

Long queue, drop priority

Any route/path

5 Traditional applications of default IP networks

Separate queue (lowest priority)

Any route/path

Separate queue, drop priority

Separate queue with preferential servicing, traffic grooming.



QoS Architectures



Currently, different QoS solutions may focus on different control loop or function entities.

User/ServiceRequirementSpecification

Admission Control

Resource management

Performance

Monitoring & Measurement

Congestion Detection

Feedback Control

Short Term Short Term ControlControl

PerformanceAnalysis

Performancestatistic

Traffic dimensioning

Long Term Long Term ControlControl

General General QoSQoS control cyclecontrol cycle



IETF IETF QoSQoS model model --IntServIntServ

IntServ (Integrated Service )IntServ is designed to provide an end to end QoSguarantee to a individual session/flow.IntServ could provide an absolute QoS guarantee to application based on the session/flow.IntServ uses RSVP protocol to reserve end to end resources for individual session/flow. IntServ entities must maintain the state info for each flow



IntServIntServ modelmodel

IETF RFC 2205



IETF IETF QoSQoS model model --DiffServDiffServ

DiffServ (Differentiated Services)DiffServ is designed to provide several classes of QoSto numbers of sessions/applicationsDiffServ could provide relative QoS guarantee based on the DiffServ classesDiffServ defines an architecture and a set of forwarding behaviors to aggregate application flows.Diffserv need a complex edge node to support packet classify while the core node could be very simple for packets forwarding.



DiffServDiffServ modelmodel

Backbone

Edge router

Core router

Edge router

Core router

IP flow

Multi-byteclassifier Meter Maker Policer

DSclassifier

Queuescheduler

TspcTspc



ITUITU--T T QoSQoS modelmodelData Plane

Buffer management, congestion avoidance, packet marking, queuing and scheduling, traffic classification, traffic policing and traffic shaping.

Control PlaneAdmission control, resource reservation, QoSrouting

Management PlaneService Level Agreement (SLA), traffic restoration, metering and recording, policy.



ITUITU--T T QoSQoS Architecture Architecture

Y.1291_F01

Control Plane

Data Plane

Admissioncontrol

Resourcereservation

QoSrouting

Buffermanagement

Queuing &scheduling

Congestionavoidance

Packetmarking

Trafficshaping

Trafficclassification

Trafficpolicing

Servicelevel

agreement

Trafficrestoration

Management p

lane

Metering

Policy

ITU-T Y.1291: An architectural framework for support of Quality of Service in packet networks



ETSI TIPHON ETSI TIPHON VoIPVoIP QoSQoS ArchitectureArchitecture

ETSI TS 101 329-3 V2.1.2



MSF MSF VoIPVoIP QoSQoS ArchitectureArchitecture

MSF Technical Report MSF-TR-QoS-001-FINAL



QOS componentsQOS componentsAdmission Control

A decision algorithm to determine whether a new flow can be granted the requested QoS without impacting earlier guarantees.

Packet ClassificationThe incoming packets could be classified in different classes based on the contents of the existing packet header(s) and/or some additional classification number added to each packet according to the defined rules.

Shapingthe process of delaying packets within a traffic stream to cause it to conform to some defined traffic profile.

Metering & MarkingThe incoming Packets could be measured and marked according to the defined rules. Shaping & Policing

Queuing & SchedulingThe incoming packets could be put into different queue and get the different treatment

SignallingService requirements negotiation protocol between user and network



SummarySummaryInternet is becoming a multi-services carrier networkDifferent users may have different requirementsDifferent services have different performance requirementInternet need QoSLots of results from IP QoS research and standardization activitiesBut there is still lack of QoS deployment



ReferencesReferencesBooks:

Zheng Wang, “Internet QoS: Architectures and Mechanisms for Quality of Service”, Morgan Kaufmann Publishers, 2001, ISBN:1-55860-608-4Kun II Park, “QoS In Packet Networks”, Springer, 2004, ISBN:0-387-23389-x

Papers:John Soldatos, Evangelos Vayias, George Kormentzas. ON THE BUILDING BLOCKS OF QUALITY OF SERVICE IN HETEROGENEOUS IP NETWORKS. IEEE Communication Surveys. Vol.7, No.1, 2005Janusz Gozdecki, etc, “Quality of Service Terminology in IP Networks”, IEEE Communications Magazine, March 2003 Xipeng Xiao and Lionel M. Ni, “Internet QoS: A Big Picture”, IEEE Network, March/April 1999ITU-T Recommendations I.350, E.800, Y.1000,Y.1010,Y.1540,Y.15413GPP TS 23.207 End-to-end Quality of Service (QoS) concept and architecture (Release 6) V6.6.0 (2005-09)ETSI TR 101 329-1 V3.1.2 (2002-01) Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 3;End-to-end Quality of Service in TIPHON systems; Part 1: General aspects of Quality of Service (QoS) ……

qos issues in heterogeneous ip networks - aalto...2006-9-8 计算机科学与技术学院...

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