1、 ETSI TR 102 024-1 V4.1.1 (2003-09)Technical Report Telecommunications and Internet ProtocolHarmonization Over Networks (TIPHON) Release 4;End-to-end Quality of Service in TIPHON Systems;Part 1: General aspects of Quality of Service (QoS)ETSI ETSI TR 102 024-1 V4.1.1 (2003-09) 2 Reference DTR/TIPHON
2、-05007R4 Keywords internet, IP, QoS, quality, telephony, VoIP ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Im
3、portant notice Individual copies of the present document can be downloaded from: http:/www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is
4、the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. In
5、formation on the current status of this and other ETSI documents is available at http:/portal.etsi.org/tb/status/status.asp If you find errors in the present document, send your comment to: editoretsi.org Copyright Notification No part may be reproduced except as authorized by written permission. Th
6、e copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2003. All rights reserved. DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members. TIPHONTMand the TIPHON logo are Trade Marks curr
7、ently being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. ETSI ETSI TR 102 024-1 V4.1.1 (2003-09) 3 Contents Intellectual Property Rights4 Foreword.4 Introduction 4 1 Scope 5 2 Refe
8、rences 5 3 Definitions and abbreviations.6 3.1 Definitions6 3.2 Abbreviations .6 4 Introduction to end-to-end Quality of Service (QoS).7 4.1 Main QoS parameters influenced by TIPHON systems .7 4.1.1 Call set-up quality.7 4.1.2 Call quality7 4.1.3 Conversational speech quality 7 4.2 Further QoS param
9、eters8 4.3 TIPHON specific QoS relevant factors 8 4.3.1 Delay Jitter8 4.3.2 Jitter buffers 9 4.3.3 Jitter Buffer Implementations .10 4.3.4 Jitter buffer monitoring capabilities11 4.4 Physical components based on which a TIPHON service may be provided 11 4.4.1 IP terminal 11 4.4.2 IP access network .
10、12 4.4.3 IP backbone 12 4.4.4 IWF (gateway/gatekeeper)12 4.4.5 SCN 13 4.4.6 Voice terminal connected to the SCN.13 5 Reference connections14 5.1 Reference connection for TIPHON scenario #0.14 5.2 Reference connection for TIPHON scenario #1.15 5.3 Reference connection for TIPHON scenario #2.15 5.4 Re
11、ference connection for TIPHON scenario #3.16 5.5 Reference connection for TIPHON scenario #4.16 5.6 Reference model for a single transport domain17 5.7 Generic reference connection for TIPHON scenarios 17 Annex A (informative): Bibliography.18 History 19 ETSI ETSI TR 102 024-1 V4.1.1 (2003-09) 4 Int
12、ellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Ri
13、ghts (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy, no investigation, including
14、IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produ
15、ced by ETSI Project Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON). The present document is part 1 of a multi-part deliverable covering end-to-end Quality of Service in TIPHON systems, as identified below: TR 102 024-1: “General aspects of Quality of Service (QoS)“; TS
16、 102 024-2: “Definition of Speech Quality of Service (QoS) Classes“; TS 102 024-3: “Signalling and Control of end-to-end Quality of Service“; TS 102 024-4: “Quality of Service Management“; TS 102 024-5: “Quality of Service (QoS) measurement methodologies“; TR 102 024-6: “Actual measurements of netwo
17、rk and terminal characteristics and performance parameters in TIPHON networks and their influence on voice quality“; TR 102 024-7: “Design guide for elements of a TIPHON connection from an end-to-end speech transmission performance point of view“; Part 8: Void; TS 102 024-9: “Call performance Classi
18、fication (Voice)“; Part 10: To be published as part of release 5 (see note) “QoS Requirements for TIPHON Terminals“; Part 11: To be published as part of release 5 (see note) “Domain by domain performance planning guidelines for end-to-end QoS objectives associated with TIPHON speech QoS classes“; TS
19、 102 024-12: “IP Telephony Service Availability“. NOTE: Quality of Service aspects of TIPHON Release 5 systems will be covered in TS 102 025 (see bibliography), and more comprehensive versions of the Release 4 documents listed above will be published as part of Release 5 as work progresses. Introduc
20、tion The present document forms one of a series of technical specifications and technical reports produced by TIPHON Working Group 5 addressing Quality of Service (QoS) in TIPHON Systems. ETSI ETSI TR 102 024-1 V4.1.1 (2003-09) 5 1 Scope The present document presents QoS related background informati
21、on for IP networks that provide voice telephony in accordance with all TIPHON scenarios. It contains: a depiction of each TIPHON scenario by its reference connection; an overview of the physical components based on which a TIPHON service may be provided. 2 References For the purposes of this Technic
22、al Report (TR) the following references apply: 1 ETSI EG 202 306: “Transmission and Multiplexing (TM); Access networks for residential customers“. 2 ETSI TS 101 314: “Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 4; Abstract Architecture and Reference Points D
23、efinition; Network Architecture and Reference Points“. 3 ETSI TS 102 024-2: “Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 4; End-to-end Quality of Service in TIPHON Systems; Part 2: Definition of Speech Quality of Service (QoS) Classes“. 4 ETSI TS 102 024-5:
24、“Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 4; End-to-end Quality of Service in TIPHON Systems; Part 5: Quality of Service (QoS) measurement methodologies“. 5 ETSI TR 102 024-7: “Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON)
25、Release 4; End-to-end Quality of Service in TIPHON Systems; Part 7: Design guide for elements of a TIPHON connection from an end-to-end speech transmission performance point of view“. 6 ITU-T Recommendation E.600: “Terms and definitions of traffic engineering“. 7 ITU-T Recommendation G.103: “Hypothe
26、tical reference connections“. 8 ITU-T Recommendation G.107: “The E-Model, a computational model for use in transmission planning“. 9 ITU-T Recommendation G.177: “Transmission planning for voiceband services over hybrid Internet/PSTN connections“. 10 ITU-T Recommendation I.350: “General aspects of qu
27、ality of service and network performance in digital networks, including ISDNs“. 11 ITU-T Recommendation P.310: “Transmission characteristics for telephone-band (300-3 400 Hz) digital telephones“. ETSI ETSI TR 102 024-1 V4.1.1 (2003-09) 6 3 Definitions and abbreviations 3.1 Definitions For the purpos
28、es of the present document, the following terms and definitions apply: best effort QoS: situation in which the end to end performance of the media stream is not defined by a service level specification end-to-end delay jitter: estimate of the statistical variance of the voice frames interarrival tim
29、e measured in milliseconds and expressed as an unsigned integer NOTE: The end-to-end delay jitter is defined to be the mean deviation (smoothed absolute value) of the difference in voice frame spacing at the receiver compared to the sender for a pair of voice frames. grade of service: Number of traf
30、fic engineering variables used to provide a measure of adequacy of a group of resources under specified conditions. These grade of service variables may be probability of loss, dial tone delay, etc. NOTE 1: The parameter values assigned as objectives for grade of service variables are called grade o
31、f service standards. NOTE 2: The values of grade of service parameters achieved under actual conditions are called grade of service results (see ITU-T Recommendation E.600 6). guaranteed QoS: situation where the end-to-end performance of the media stream, for the duration of a session, is designed t
32、o meet the requirements laid down in a service level specification NOTE: The service level specification may include details of the percentage of the time when quality may fall below specified levels as well as the distribution and duration of the intervals when this occurs. interarrival jitter: est
33、imate of the statistical variance of the RTP data packet interarrival time measured in milliseconds and expressed as an unsigned integer NOTE: The interarrival jitter is defined to be the mean deviation (smoothed absolute value) of the difference in packet spacing at the receiver compared to the sen
34、der for a pair of packets. jitter amplitude: absolute difference in arrival time between the fastest and the slowest data packet or voice frame 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: ADSL Asymmetric Digital Subscriber Line BRAN Broadband Radio
35、Access Networks FDM Frequency Division Multiplex GSM Global System for Mobile communications ISDN Integrated Services Digital Network IP Internet Protocol ITU International Telecommunication Union ITU-T ITU Telecommunication standardization sector (former CCITT) IWF InterWorking Function LAN Local A
36、rea NetworkPSTN Public Switched Telephone Network QoS Quality of Service RTP Real Time Protocol SCN Switched Communications Network TDM Time Division Multiplex UMTS Universal Mobile Telecommunications System VDSL Very high speed Digital Subscriber Line xDSL ADSL, VDSL and other Digital Subscriber Li
37、ne Techniques ETSI ETSI TR 102 024-1 V4.1.1 (2003-09) 7 4 Introduction to end-to-end Quality of Service (QoS) 4.1 Main QoS parameters influenced by TIPHON systems End-to-end QoS in a TIPHON system is characterized in the TIPHON QoS documentation under two broad headings: call set-up quality; and cal
38、l quality. 4.1.1 Call set-up quality Call set-up quality is mainly characterized by the call set-up time which is perceived by the user as the responsiveness of the service. Call set-up time is the time elapsed from the end of the user interface command by the caller (keypad dialling, E-mail alias t
39、yping, etc.) to the receipt by the caller of a meaningful progress information. The present document provides the exact definition of the various call set-up times for use in TIPHON systems, whereas ITU-T Recommendation E.600 6 provides more information on the definition of post-dialling delay in SC
40、N systems. 4.1.2 Call quality Call quality is characterized by the overall transmission quality rating R. Overall transmission quality rating (R) describes the full acoustic-to-acoustic (mouth to ear) quality, experienced by a user, for a typical situation using a “standard“ telephony handset. The o
41、verall transmission quality rating is calculated using the E-Model (see ITU-T Recommendation G.107 8). For calculation purposes the use of traditional telephone handsets (see ITU-T Recommendation P.310 11) at both sides of the connection is assumed. Within the overall transmission quality two major
42、factors contribute to the overall QoS experience of the user of the TIPHON system: end-to-end delay: this mainly impacts the interactivity of a conversation. The measurement is done from the mouth of the speaker to the ear of the listener; and end-to-end speech quality: this is the one way speech qu
43、ality as perceived in a non interactive situation. The measurement methodologies for these parameters are specified in TS 102 024-5 4, while the requirements for these parameters with respect to the various TIPHON QoS classes are defined in TS 102 024-2 3. TR 102 024-7 5 provides guidance on these p
44、arameters with respect to the practical design phase of equipment and networks. 4.1.3 Conversational speech quality The conversational quality of a telephone link is influenced by four parts: Listening quality, the quality of the speech received from the talkers voice at the other side, dominated by
45、 noise and speech distortion. Talking quality, the quality of the speech received from the talkers own voice, dominated by echo and sidetone distortion. Interaction quality, the quality associated with the alternation of talking and listening, dominated by end-to-end delay and noise/speech switching
46、. Background noise transmission quality, the quality of the transmission of background noises received from the other side. Note that Background noise transmission quality and Listening quality are not independent: the first may or may not have been included in the latter. ETSI ETSI TR 102 024-1 V4.
47、1.1 (2003-09) 8 4.2 Further QoS parameters In general, Quality of Service (QoS) is determined by a multitude of further QoS parameters; guidance in this field is provided by ITU-T Recommendation I.350 10. For the complexity of other QoS parameters it is considered that: they either do not apply to T
48、IPHON systems; or the TIPHON systems have similar influence on those parameters like other telephony systems. 4.3 TIPHON specific QoS relevant factors Examples of TIPHON specific QoS relevant factors are: number of hops; possible variation of the geographical length of one connection during the talk
49、ing state; occurrence of congestion; use of prioritization or bandwidth reservation schemes; jitter and jitter buffer behaviour (see clauses 4.3.1 through 4.3.4). TR 102 024-7 5 provides guidance on these factors with respect to the practical design phase of equipment and networks. 4.3.1 Delay Jitter Packetized transmission systems exhibit variable delay in packet delivery time; this is caused by the fact that different packets carrying speech samples of the same telephone conversation may be transported
