1、Report No. 53 A Technical ReportonJune 1997 Transmission PerformanceGuidelines for ATMTechnology Intended forIntegration Into NetworksSupporting VoicebandServicesPrepared byT1A1.7Working Groupon Signal Processing andNetwork Performance forVoiceband ServicesCommittee T1 is sponsored by the Alliance f
2、or Telecommunications Industry SolutionsAccredited by the American National Standards InstituteCopyright 1997 by Alliance for Telecommunications IndustrySolutionsAll rights reserved.No part of this publication may be reproduced in any form,in an electronic retrieval system or otherwise, without thep
3、rior written permission of the publisher.A Technical Report onTransmission Performance Guidelines for ATMTechnology Intended for Integration IntoNetworks Supporting Voiceband ServicesAbstractThis Technical Report addresses the performance parameters that should be considered forATM Technology intend
4、ed for integration into networks which support voiceband services. Thedocument provides discussion on ATM technology that performs one or more of the followingfunctions: echo canceller function; interworking function (Between the ATM and the non-ATMdomain); multiplexing function; switching function;
5、 and transport function. Guidelines foracceptable transmission performance operating limits for these ATM functional networkelements are provided. These guidelines will assist manufacturers in the design of this ATMtechnology and network implementers in understanding and specification of the paramet
6、ersrequired to properly identify the performance requirements of equipment they wish to acquire.Because the guidelines presented in this report are based only on voice transmission qualitycriteria, it should be noted that other criteria, e.g. the ability of these devices to support digitaldata and m
7、ultimedia services, may present a requirement for more restrictive performanceparameter thresholds.Document T1A1.7/97-001r3Prepared byT1A1.7Working Group on Signal Processing andNetwork Performance for Voiceband ServicesiiFOREWORDThis T1 Technical Report was initiated in the T1A1.7 Working Group on
8、Signal Processing andNetwork Performance for Voiceband Services. The Technical Report builds on the industryagreements reached during the development of T1 Technical Report 46, TransmissionPerformance Standards Issues Regarding the Introduction of ATM Technology into NetworksSupporting Voiceband Ser
9、vices. The Technical Report provides manufacturers and networkimplementers with performance guidelines concerning the voice parameters associated withATM technology intended for implementation into networks supporting voiceband services.Accordingly, this document should not be viewed nor interpreted
10、 to be a T1 StandardsDocument.Suggestions for improvement of the Technical Report are welcome and should be sent to theAlliance for Telecommunications Industry Solutions - Committee T1 Secretariat, 1200 G StreetN.W., Suite 500, Washington, D.C. 20005.iiiCONTENTS1 Introduction 12 Scope 13 References
11、34 Definitions.45 ATM Technology Performing an Echo Canceller Function66 ATM Technology Performing a Multiplexer Function.157 ATM Technology Performing a Transport System Function .238 ATM Technology Performing a Switching Function (Digital Interfaces Only) 319 ATM Technology Performing a Switching
12、Function (Digital interworking function(Between the ATM and the non-ATM domain); multiplexing function; switching function; andtransport function.In 1996 T1 Technical Report No. 46, Transmission Performance Standards Issues Regardingthe Introduction of ATM Technology into Networks Supporting Voiceba
13、nd Services, wasissued. The focus of the work during the preparation of T1 Technical Report No. 46 was toidentify where standards work was required to allow for an orderly integration of ATMtechnology into networks which support voiceband services. Technical discussions continuedin T1A1.7 in 1996 an
14、d 1997 focusing on the areas where work was required, as identified in T1Technical Report No. 46. This Technical Report was generated to capture the industryagreements reached during these discussions and present them as technical guidelines.Thus, this Technical Report identifies and recommends the
15、set of performance parameters thatshould be considered for specification of ATM Technology intended to support voicebandservices. Additionally, it provides guidelines for the performance values associated with theseparameters. These guidelines will assist manufacturers in the design of ATM technolog
16、y andfacilitate network design and equipment procurement by network implementers. Because theguidelines presented in this report are based only on voiceband transmission quality criteria, itshould be noted that other criteria, e.g. the ability of these devices to support digital data andmultimedia s
17、ervices, may present a requirement for more restrictive performance parameterthresholds. Therefore, this document should not be construed to be a T1 Technical Standard.The network elements considered in this document are intended to be the same as thosepresented in the T1 Technical Report No. 46. AT
18、M technology performing other functionalityare not intended to be excluded by the approach taken within this document. This documentalso addresses those situations where the performance is configuration dependent.This work represents a fundamental step towards improving the connection betweenvoiceba
19、nd service needs and ATM technology standards.2 ScopeThis document currently considers the following ATM technology that may be used to supportvoiceband services:Digital Signal Processing Unit operating as a Cell Based Echo Canceller;Interworking Unit (Between ATM and non-ATM Operating Domains);Mult
20、iplexers;Switches (with digital only interfaces);Switches (with analog and digital interfaces); andTransport systems that use ATM technology.Technical Report No. 532The document is written in the form of a Performance Requirements Document and eachsection that deals with a particular ATM functional
21、technology operating arrangement ispresented as a self standing section. The performance guidelines presented for eachfunctional technology unit must be considered in the context of the end-to-end network ofwhich it is a part. Such performance values will usually be similar to those performance valu
22、esspecified for equipment that does not use ATM technology. When units perform more thanone function, the guidelines identified for each function should be met. The list of parametersfor which requirements have been provided was obtained from T1 Technical Report No. 46Table 1. The word “requirement”
23、 has a special meaning within the context of this document.As this is a Technical Report, and not a Technical Standard, it does not define requirements inthe normal sense. Rather, the term “requirement” in this document should be interpreted tomean, the current recommended provisional value to be us
24、ed until more formal guidance in theform of a public standard is made available.The format used to present the requirements is consistent. The parameter is identified first.Parameter definitions are provided in Annex 1 to this document. A discussion section isprovided as needed to provide informatio
25、n relevant to the parameter or the parameterthreshold. Because each section is intended to be self standing, there will be instances wherethe same information is repeated in more than one requirements section. For those parameterthresholds that are configuration dependent, a reference is provided to
26、 the appropriate sectionwhere the pertinent information can be found.This document assumes that the performance requirements of ITU-T Recommendation I.356are met on an end to end basis. As a result, a network element can thus be considered tooperate error free, from an embedded signal point of view,
27、 for any short duration test. Thus,the guidelines were generated on the assumption that there were no cell loss occurrences; noerrored cells; no misinserted cells; and switches were adequately designed and traffic loadingwas controlled so as to ensure there were not lost cells due to CDV or traffic
28、blocking. Thisassumption used in the generation of these requirements was not intended to imply that theseconsiderations are not important. Rather, that these assumptions are valid for a typicallaboratory test evaluation situation. It should be noted that in the context of an operatingnetwork, busin
29、ess forces may cause these assumptions to be invalid, however, thedegradation which results should not occur due to poor technology, but rather due toprovisioning methods and actual traffic loading conditions.The test set up should not generate errored conditions, e.g. lost or misinserted cells, dur
30、ingcompliance testing.This document recognizes that the current set of guidelines are a subset of a total set ofstandard tests required to fully evaluate this ATM technology and thus they can be expected toevolve through the addition of new tests to evaluate other aspects of the technology. Forexamp
31、le, the current suite of tests do not address how the ATM technology should react to:errored cells; lost cells; and misinserted cells.This document assumes that these ATM technology devices interface at standard line rates,e.g. DS-1, DS-3, STS-1. The requirements for these interfaces can be found in
32、 other ANSIstandards and thus these requirements are not contained within this document. Further, theguidelines provided in this document are not contained in the interface standards documents.Technical Report No. 5333 ReferencesThe following standards, recommendations and other publications have be
33、en referenced inthis document and are understood to contain material that would be helpful in providingguidance during the process of generating firm industry agreements, i.e. standards, associatedwith ATM hardware. The latest version of the recommendations should be used.ANSI/EIA/TIA-579-1991, Acou
34、stic-to-Digital and Digital-to-Acoustic TransmissionRequirements for ISDN TerminalsANSI/IEEE Std 100-1988, IEEE Standard Dictionary of Electrical and Electronics TermsANSI/IEEE Std 743-1995, IEEE Standard Equipment Requirements and MeasuringTechniques for Analog Transmission Parameters for Telecommu
35、nicationsANSI/T1.102-1993, Digital Hierarchy - Electrical InterfacesANSI/T1.506-1997, Network Performance - Transmission Specifications for SwitchedExchange Access NetworkANSI/T1.508-1992, Network Performance - Loss Plan for Evolving Digital NetworksT1 Technical Report No. 46, Transmission Performan
36、ce Standards Issues Regarding theIntroduction of ATM Technology into Networks Supporting Voiceband ServicesITU-T Blue Book, Fascicle 1.3, DefinitionsITU-T Recommendation G.113 (02/96), Transmission ImpairmentsITU-T Recommendation G.114 (02/96), One Way Transmission TimeITU-T Recommendation G.122 (03
37、/93), Influence of National Systems on Stability Talker Echoin International ConnectionsITU-T Recommendation G.126 (03/93), Listener Echo in Telephone NetworksITU-T Recommendation G.131 (08/96), Control of Talker EchoITU-T Recommendation G.132 (1988), Attenuation DistortionITU-T Recommendation G.164
38、 (1988), Echo SuppressorsITU-T Recommendation G.168 (1997), Digital Network Echo CancellersITU-T Recommendation G.712 (09/92), Transmission Performance Characteristics of PulseCode ModulationITU-T Recommendation I.356 (11/93), B-ISDN ATM Layer Cell Transfer PerformanceTechnical Report No. 534ITU-T R
39、ecommendation I.361 (11/95), B-ISDN ATM Layer SpecificationITU-T Recommendation I.ATMV (Draft Version 6.3), Voice and Voiceband Data Transport inATM NetworksITU-T Recommendation Q.552 (01/94), Transmission Characteristics at 2-Wire AnalogInterfaces of Digital ExchangesTransmission Systems for Commun
40、ications, Fourth Edition, Bell Telephone Laboratories,Incorporated, 19704 DefinitionsAsynchronous Transfer Mode (ATM)The term applied to a technology that is based on the premise that information is transported incells. Specifically, in this document ATM is used to apply to technology that uses ITU-
41、TRecommendation I.361 B-ISDN ATM Layer Specification for ATM cell size and makeup, viz. 53octets per cell with 5 cells allocated for the header and 48 cells allocated to carry payloadinformation.1ATM Digital Processing FunctionThe term applied to ATM technology that operates with standard line rates
42、 on both the inputsand the outputs, e.g. DS3 on the input and DS3 on the output, and which modifies thecontents of the cells as they pass through in some prescribed manner. This device maymodify none, some, or all of the cells that pass through it. This cell modification is intended tochange the tra
43、nsmission characteristics of the signals in the virtual connections, e.g. thisdevice may perform echo cancellation or speech compression on some or all the virtualconnections that pass through it.ATM MultiplexerThe term applied to a cell multiplexing device that operates with standard line rates on
44、both theinputs and the outputs, e.g. DS1 on the input and DS3 on the output, and which passes thecells received on the input to the output. The relationship between input and output, i.e. virtualcircuits, does not change on a per call basis, i.e. only permanent virtual circuits are supported.This de
45、vice does not allow blocking or compression.ATM Transport SystemThe term applied to a transport system that is comprised of a carrier system that is terminatedby an ATM multiplexer at each end. The relationship between input and output, i.e. virtualcircuits, cannot change on a per call basis, i.e. p
46、ermanent virtual circuits only are supported.This device does not allow blocking or compression.1 The 48-octet payload can be apportioned for various purposes, e.g., I.ATM-V uses forty-seven (47) octets forthe voiceband signal and one (1) for control information.Technical Report No. 535ATM Switch (D
47、igital Interfaces Only)The term applied to ATM technology that operates with standard digital line rates on both theinputs and the outputs, e.g. DS1 on the input and DS3 on the output, and which passes thecells received on the input to the output. The relationship between input and output, canchange
48、 on a per call basis, i.e. switched virtual circuits must be supported and permanentvirtual circuits may be supported. This device allows blocking and may perform compressionor expansion on the individual virtual path cell streams.At the current time there is no industry agreement that compression w
49、ill be performed within anATM switch.ATM Switch ( Analog and Digital Interfaces)The term applied to ATM technology that operates with analog 2-wire inputs on the drop side,i. e., subscriber line side or access line side, of the switch (4 wire may be supported as well)and standard digital line rates on both the inputs and the outputs, e.g. DS1 on the input andDS3 on the output, and which passes the cells received on the input to the output. Therelationship between input and output, can change on a per call basis, i.e. switched virtualcircuits must be supported and permanent virtual ci
