1、 International Telecommunication Union ITU-T G.799.3TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2011) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments Other terminal equipment Signal processing functionality and performance of an IP-to-IP voi
2、ce gateway optimized for the transport of voice and voiceband data Recommendation ITU-T G.799.3 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRI
3、ER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION O
4、F RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 General G.700G.709 Coding of voice and audio signals G.710G.729 Principal characteristics of primary multiplex equipment G.730G.739 Principal charac
5、teristics of second order multiplex equipment G.740G.749 Principal characteristics of higher order multiplex equipment G.750G.759 Principal characteristics of transcoder and digital multiplication equipment G.760G.769 Operations, administration and maintenance features of transmission equipment G.77
6、0G.779 Principal characteristics of multiplexing equipment for the synchronous digital hierarchy G.780G.789 Other terminal equipment G.790G.799DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECT
7、S G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.799.3 (05/2011) i Recommendatio
8、n ITU-T G.799.3 Signal processing functionality and performance of an IP-to-IP voice gateway optimized for the transport of voice and voiceband data Summary As a consequence of the growth of IP and of IP services, different operators have an increased need to support bulk interconnection of voice an
9、d voiceband data traffic at the IP level. Recommendation ITU-T G.799.3 defines the signal processing functionality and performance of an IP-to-IP gateway that is optimized for the transport of voice and voiceband data. Such a gateway may be used by network operators for the bulk interconnection of v
10、oice and voiceband data traffic at the IP level. This Recommendation addresses the following areas of such an IP-to-IP gateway: codec transcoding packetization time, voice performance, facsimile, voiceband data and text telephone support, support and performance of in-band signalling tones, and jitt
11、er handling. This Recommendation does not define any new protocols but, where necessary, refers to existing protocols developed within the ITU or by other standards bodies such as the IETF. The support of tandem-free operation (TFO) and other in-band mechanisms for improving speech quality by avoidi
12、ng tandem codecs will be developed in future editions of this Recommendation. History Edition Recommendation Approval Study Group 1.0 ITU-T G.799.3 2011-05-14 16 ii Rec. ITU-T G.799.3 (05/2011) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the f
13、ield of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standard
14、izing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is cover
15、ed by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indica
16、te both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved
17、 when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PRO
18、PERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asser
19、ted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that
20、this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2012 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. I
21、TU-T G.799.3 (05/2011) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 3 3.1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendation . 3 4 Abbreviations and acronyms 3 5 General description of an IP-to-IP voice gateway 4 5.1 IP-to-IP Voice gateway in the NGN functional
22、architecture 4 5.2 ITU-T H.248 profile . 5 6 Functionality . 6 6.1 Transcoding 6 6.2 Packetization time conversion 6 6.3 Jitter reduction (for further study) 7 6.4 Support for facsimile, voiceband data and text telephone traffic . 8 6.5 Support for in-band signalling tones 8 7 Testing and performanc
23、e measurements 10 7.1 Testing methodology 10 8 RTCP XR support (for further study) 12 8.1 Generation and forwarding of RTCP XR . 12 Appendix I IP-to-IP gateway scenarios 14 I.1 Scenario 1: Same codec, same packet size, no jitter buffer 14 I.2 Scenario 2: Same codec, same packet size, jitter buffer i
24、ntroduced to protect Network A from Network Bs jitter 14 I.3 Scenario 3: Same codec, different packet size . 15 I.4 Scenario 4: Different codec, different packet size 16 Rec. ITU-T G.799.3 (05/2011) 1 Recommendation ITU-T G.799.3 Signal processing functionality and performance of an IP-to-IP voice g
25、ateway optimized for the transport of voice and voiceband data 1 Scope This Recommendation defines the signal processing functionality and performance of an IP-to-IP gateway that is optimized for the transport of voice and voiceband data. Such a gateway may be used by network operators for the bulk
26、interconnection of voice and voiceband data traffic at the IP level. This is not meant to restrict an IP-to-IP gateway from being used within one providers network. The following areas are addressed by this Recommendation: 1) Codec transcoding 2) Packetization time 3) Voice performance 4) Facsimile,
27、 voiceband data and text telephone support and performance 5) Support and performance of in-band signalling tones 6) Jitter handling. This Recommendation does not define any new protocols but, where necessary, refers to existing protocols developed within the ITU or by other standards development or
28、ganizations. Support of tandem-free operation (TFO) and other in-band mechanisms for improving speech quality by avoiding tandem codecs is for further study in this Recommendation. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in th
29、is text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edi
30、tion of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.107 Recommendation IT
31、U-T G.107 (2009), The E-model: a computational model for use in transmission planning. ITU-T G.113 Recommendation ITU-T G.113 (2007), Transmission impairments due to speech processing. ITU-T G.114 Recommendation ITU-T G.114 (2003), One-way transmission time. ITU-T G.177 Recommendation ITU-T G.177 (1
32、999), Transmission planning for voiceband services over hybrid Internet/PSTN connections. ITU-T G.711 Recommendation ITU-T G.711 (1988), Pulse code modulation (PCM) of voice frequencies. ITU-T G.722 Recommendation ITU-T G.722 (1988), 7 kHz audio-coding within 64 kbit/s. ITU-T G.722.2 Recommendation
33、ITU-T G.722.2 (2003), Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). 2 Rec. ITU-T G.799.3 (05/2011) ITU-T G.723.1 Recommendation ITU-T G.723.1 (2006), Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s. ITU-T G.726 Reco
34、mmendation ITU-T G.726 (1990), 40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM). ITU-T G.728 Recommendation ITU-T G.728 (1992), Coding of speech at 16 kbit/s using low-delay code excited linear prediction. ITU-T G.729 Recommendation ITU-T G.729.1 (2007), Reduced complexity 8
35、 kbit/s CS-ACELP speech codec. ITU-T G.729.1 Recommendation ITU-T G.729.1 (2006), G.729-based embedded variable bit-rate coder: An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729. ITU-T G.1020 Recommendation ITU-T G.1020 (2006), Performance parameter definitions for quality of
36、 speech and other voiceband applications utilizing IP networks. ITU-T G.1050 Recommendation ITU-T G.1050 (2007), Network model for evaluating multimedia transmission performance over Internet Protocol. ITU-T H.248 Recommendation ITU-T H.248 (2000), Gateway control protocol. ITU-T H.248.1 Recommendat
37、ion ITU-T H.248.1 (2005), Gateway control protocol: Version 3. ITU-T H.248.30 Recommendation ITU-T H.248.30 (2007), Gateway control protocol: RTCP extended performance metrics packages. ITU-T P.805 Recommendation ITU-T P.805 (2007), Subjective evaluation of conversational quality. ITU-T P.862 Recomm
38、endation ITU-T P.862 (2001), Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs. ITU-T P.1010 Recommendation ITU-T P.1010 (2004), Fundamental voice transmission objectives for VoIP terminals
39、 and gateways. ITU-T Q.3303.2 Recommendation ITU-T Q.3303.2 (2007), Resource control protocol No. 3 Protocol at the interface between a Policy Decision Physical Entity (PD-PE) and a Policy Enforcement Physical Entity (PE-PE) (Rw interface):H.248 Alternative. ITU-T T.38 Recommendation ITU-T T.38 (200
40、7), Procedures for real-time Group 3 facsimile communication over IP networks. ITU-T V.150.1 Recommendation ITU-T V.150.1 (2003), Modem-over-IP networks: Procedures for the end-to-end connection of V-series DCEs. ITU-T V.151 Recommendation ITU-T V.151 (2006), Procedures for the end-to-end connection
41、 of analogue PSTN text telephones over an IP network utilizing text relay. ITU-T V.152 Recommendation ITU-T V.152 (2005), Procedures for supporting voice-band data over IP networks. Rec. ITU-T G.799.3 (05/2011) 3 ITU-T V.153 Recommendation ITU-T V.153 (2009), Interworking between ITU-T T.38 and ITU-
42、T V.152 using IP peering for real-time facsimile services. ITU-T Y.1540 Recommendation ITU-T Y.1540 (2007), Internet protocol data communication service IP packet transfer and availability performance parameters. ITU-T Y.2012 Recommendation ITU-T Y.2012 (2006), Functional requirements and architectu
43、re of the NGN release 1. IETF RFC 3550 IETF RFC 3550 (2003), RTP: A Transport Protocol for Real-Time Applications. IETF RFC 3611 IETF RFC 3611 (2003), RTP Control Protocol Extended Reports (RTCP XR). IETF RFC 4733 IETF RFC 4733 (2006), RTP Payload for DTMF Digits, Telephony Tones, and Telephony Sign
44、als. TIA-1016 TIA-1016 (2004), Source-Controlled Variable-Rate Multimode Wideband Speech Codec (VMR-WB) Service Options 62 and 63 for Spread Spectrum Systems. 3 Definitions 3.1 Terms defined elsewhere 3.1.1 transcoding ITU-T V.152: Transcoding in general is the translation from one type of encoded m
45、edia format to another different media format (examples for media type “voice“: ITU-T G.711 A-law to -law or vice versa, ITU-T G.711 codec to ITU-T G.726-40K, ITU-T G.711 to a broadband codec that operates at 256 kbit/s, etc.). 3.2 Terms defined in this Recommendation This Recommendation defines the
46、 following term: 3.2.1 IP-to-IP voice gateway: Is a bearer level gateway (e.g., like ITU-T H.248 controlled media gateways), which provides interworking functions (or peering) between two IP domains. The term “voice“ indicates that the gateway is optimized for voice, voiceband data, or 164 circuit-m
47、ode data services, and that the level of interworking may also be above the IP layer (e.g., similar to layer 5 (session) peering). The term “IP-to-IP“ indicates that there is only unicast traffic at the gateway. NOTE The IP-to-IP voice gateway relates to an ITU-T H.248 controlled media gateway (MG)
48、with two IP-based ephemeral terminations per context ITU-T H.248. Depending on the various scenarios, the interworking might be “media-agnostic“ or “media-aware“, or even “transport-protocol agnostic“. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms. CD
49、MA Code Division Multiple Access FoIP Facsimile-over-IP GCP Gateway Control Protocol GSM Global System for Mobile communication IP Internet Protocol IPDV IP Packet Delay Variation 4 Rec. ITU-T G.799.3 (05/2011) IPTD IP Packet Transfer Delay MG Media Gateway MGC Media Gateway Controller MoIP Modem-over-IP MOS-CQS MOS Conversational Quality Subjective MOS-LQO MOS Listening Quality Objective NAPT Network Address And Port Translation NGN Next Gen
