1、TR 1 O1 094 1.1.1 (1997-09) Technical Report Network Aspects (NA); Broadband Integrated Services Digital Network (B-ISDN); ATM for the transport of 64 kbits narrowband channels - STD-ETSI TR 101 074-ENGL 1777 m 3400855 0234b17 75T 2 TR 101 094 V1.l.l (1997-09) Reference DTWNA-052112 (a4000ics.PDF) K
2、eywords ATM, B-ISDN, trunking ETSI Secretariat Postal address F-O6921 Sophia Antipolis Cedex - FRANCE Office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Siret Na 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre a la Sous-Prfecture de Grasse (06) No 7803/8
3、8 Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 X.400 c= fr; a=atlas; p=etsi; s=secretariat internet secretariata etsi.fr http:/www.etsi .fr Copyright Notjfication No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproductio
4、n in ail media. O European Telecommunications Standards Institute 1997. AU rights reserved. I STD-ETSI TR 101 074-ENGL 1777 34UU855 0234b20 244 Ip 3 TR 101 094 Vl.l.1 (1997-09) Contents Intellectual Property Rights 5 Foreword 5 Introduction 5 1 Scope 7 2 References 8 3 Definitions, symbols and abbre
5、viations . 9 3.1 Definitions . 9 3.2 Symbols and abbreviations 9 4 ATM trunking mechanisms 10 5 Switched tninking 11 5 . 1 Common functions . 11 5.1.1 Reference configuration . . 11 5.1.2 Functionality of the Interworking Function (M) . 11 5.1.3 IWF reference model 13 5.1.4 Signalling . . 13 5.1.4.1
6、 N-ISDN signalling . . 13 5.1.4.2 13 5.1.4.3 . . 13 5.1.5 OAM . 14 5.1.6 5.1.7 Timing 14 5.1.7.1 Timing scenarios . 14 5.1.7.3 Timing options 16 5.1.8 Management . . 18 ATM Adaptation Layer (AAL) . 5.1.7.2 Timing requirements . 16 5.2 Trunking based on one-to-one mapping . 18 5.2.1 AAL . 19 5.3 Trun
7、king based on many-to-one mapping 19 5.3.1 AAL . 19 5.4 Trunking based on hybrid multiplexing . 19 5.4.1 AAL . 20 6 6.1 6.1.1 6.1.2 6.1.3 6.1.4 6.2 6.2.1 6.2.2 6.2.3 6.3 6.3.1 6.3.2 6.3.3 6.4 6.4.1 6.4.2 CES Trunking . 20 Functional requirements . Definition of the interface point . Interconnection
8、capability at IWF . 21 Functional allocation 21 Applicability and limits 21 Signalling requirements 21 Target signalling protocol . 22 Conversion of signalling Bandwidth allocation QoS requirements of the ATM network . 22 Reference configuration 22 Performance parameter Related issues 22 QoS effects
9、 on narrowband services . 23 Availability . . 23 Limitations . 23 . 6.5 OAM 23 6.6 AAL . . 23 6.7 Management . . 23 7 7.1 7.1.1 7.1.2 7.1.3 7.1.4 7.2 7.2.1 7.2.2 7.2.3 7.3 7.3.1 7.3.2 7.3.3 7.4 7.4.1 7.4.2 7.5 7.6 7.7 8 8.1 8.2 8.3 8.4 4 TR 101 094 Vl.l.1 (1997-09) Trunking based on service interwor
10、king 23 Functional requirements . 23 Definition of the interface point . . 23 Interconnection capability at iWF . 24 Functional allocation 24 Applicability and limits . 24 Signalling requirements . 24 Conversion of signalling . 24 Bandwidth allocation . 24 Target signalling protocol 25 QoS requireme
11、nts to the ATM network . 25 Reference configuration . 25 Performance parameter 25 Related issues . 25 QoS effects on narrowband services 25 Avail ability Limitations 25 om . 25 AAL . 25 Conclusions 26 Switched trunking . 26 Service interworking 26 Management . . 25 Circuit emulation service 26 Summa
12、ry 26 n- History LI STDeETSI TR LOL OSLI-ENGL 1797 I34013855 O234622 DL7 W 5 TR 101 094 V1.l.l (1997.09) Intellectual 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 publicl
13、y available for ETSI members and non-members , and can be found in ETR 314: “lntellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETS1 standards“, which is available free of charge from the ETSI Secretariat. Latest updates are available on the
14、 ETSI Web server (http:/www.etsi.fi/ipr). Pursuant to the ETSI Interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETR 314 (or the updates on http:/www.etsi.fr/ipr) which are, or may
15、 be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by ETSI Technical Committee Network Aspects (NA). The present document describes the requirements for the transport of 64 kbit/s narrowband channels between narrowband public networks across
16、a public Asynchronous Transfer Mode (ATM) based Broadband integrated Services Digital Network (B-ISDN). Introduction With the introduction of ATM backbone infrastructures into public telecommunications networks, the provision of a range of broadband services, e.g. high speed LAN interconnect and vir
17、tual private networking, is being enabled. These broadband services are targeted initially at the business user, but with the proliferation of broadband terminals and the accompanying economies of scale they will ultimately become available to the residential user as well. Nevertheless, it is well r
18、ecognized that for many years to come, the present generation of 64 kbit/s narrowband public networks will need to Co-exist and intenvork with the evolving B-ISDN. The present document concentrates on the provision of one of the narrowbandhroadband intenvorking requirements, namely ATM trunking for
19、the support of 64 kbit/s narrowband channels. An ATM trunk is defined here as one or more ATM virtual connections that carries a number of 64 kbit/s narrowband channels and the associated narrowband signalling. No constraints are placed on the number N of narrowband channels transported in an ATM tr
20、unk, so that N may vary from 1 to some arbitrarily large number, depending on the application being served and the chosen trunking method. A general objective for ATM trunking is the efficient use of B-ISDN resources in the support of 64 kbit/s narrowband channels. The use of ATM trunking in support
21、 of services employing, e.g. low bit rate coding and silence suppression techniques, in which the number of user channels supported may vary dynamically, is for further study. 6 TR 101 094 V1.l.l (1997-09) Reference configuration Figure 1 shows the reference configuration for ATM trunking of narrowb
22、and channels. Figure 1: Reference Configuration for ATM Trunking in the above reference configuration, 7 types of trunking services are represented: i) 2) 3) 4) 5) 6) 7) ATM trunking between private narrowband networks across a private ATM network; ATM trunking between private narrowband networks ac
23、ross a public ATM network; ATM trunking between public narrowband networks across a public ATM network; ATM tmnking between private and public narrowband networks across a private ATM network; ATM trunking between private narrowband networks across concatenated private and public ATM networks; ATM t
24、runking between public narrowband networks across a private ATM network; ATM trunking between private and public narrowband networks across a public ATM network. The ATM trunking service represented as type 3) in figure 1 is the focus of the present document; consideration of other service types is
25、for further study. STD.ETS1 TR LO1 074-ENGL 1797 Is 3400855 023YbL9 522 7 TR 101 094 V1.l.l (1997-09) 1 Scope The present document defines the requirements for ATM trunking, which may be used for the transport of 64 kbit/s narrowband channels across an ATM-based B-ISDN. These requirements include: t
26、he use of switched ATM virtual connections including interworking between N-ISUP and B-ISUP; the use of ATM virtual connections, both permanent and switched, including circuit emulation. Figure 2: ATM Trunking Scenario Figure 2, adapted from ITU-T Recommendation 1.580 i, illustrates the scope of the
27、 present document. As shown in the figure, one or more public narrowband networks interfaces with a public broadband network by means of interworking functions (IWFs). ATM trunking is used for the transport of 64 kbit/s narrowband channels between the narrowband networks across the ATM network via t
28、he Ws. in the present document, only “static“ trunking is defined, in which the ATM trunk supports a fixed number of narrowband channels. For reasons of clarity and simplicity, figure 2 shows only a restricted number of Ws, although any number may be connected between the narrowband network(s) and t
29、he ATM network commensurate with the overall network architectural requirements and policy. For a complete definition of ATM trunking requirements, the scope of the present document will include: definition of the functionality of the IWF between narrowband and broadband networks; description of the
30、 relationships between the functions comprising the IWF; definition and description of any relevant control plane aspects of ATM trunking; definition and description of any relevant management plane aspects of ATM trunking; definition of any timingsynchronization requirements specific to ATM trunkin
31、g. The above scope is applied to each of the multiple ATM trunking methods documented in the present document. The advantages and drawbacks associated with each of the methods is also discussed in order to give readers an appreciation of the differences in performance that can be expected. STD-ETSI
32、TR 101 094-ENGL 1777 3400855 0234b18 b7b = a TR 101 094 Vl.l.1 (1997-09) G en eral i n te two rki ng req u i remen ts A number of general requirements in respect of interworking between narrowband and broadband networks applies, including the following. No retrospective requirements shall be placed
33、on existing networks by the ATM trunking mechanism employed. 0 Voice and voiceband data (not precluding X.25 and Frame Relay over ISDN) shall be carried transparently in the user plane of the ATM infrastructure. Any routeing, switching or signalling requirements of the individual trunking mechanisms
34、 will be explicitly defined. Traffic characterization ATM trunking can be supported by the Deterministic Bit Rate (DBR) Transfer capability, as defined in draft RU-T Recommendation 1.371 3. If 64 kbith PCM samples are directly encoded into ATM cells with no low rate encoding or silence suppression,
35、then a Constant Bit Rate (CBR) connection is used. If low rate encoding or silence suppression is used, then an on-demand-bandwidth connection is required; this type of capability is for further study. 2 Ref ere nces References may be made to: specific versions of publications (identified by date of
36、 publication, edition number, version number, etc.), in which case, subsequent revisions to the referenced document do not apply; or all versions up to and including the identified version (identified by “up to and including“ before the version identity); or all versions subsequent to and including
37、the identified version (identified by “onwards“ following the version identity); or publications without mention of a specific version, in which case the latest version applies. A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number.
38、 111 ITU-T Recommendation 1.580: “General arrangement for intenvorking between B-ISDN and 64 kbith ISDN. i21 ITU-T Recommendation 1.363.1: “B-ISDN ATM Adaptation Layer (AAL) Specification, Type 1 and 2. i31 41 ITU-T Recommendation 1.371: “Traffic Control and Congestion Control in B-ISDN. ITU-T Recom
39、mendation Q.2963: “B-ISDN DSS 2 Connection modification“. PI i61 ITU-T Recommendation G.711: “milse Code Modulation (PCM) of voice frequencies“. ITU-T Recommendation 1.75 1 : “Asynchronous Transfer Mode Management of the Network Element View“. 71 TCR-TR 044: “Vocabulary for B-ISDN“, i81 191 IT-T Rec
40、ommendation 1.610: “B-ISDN operation and maintenance principles and functions“. ETR 263: “Broadband Integrated Services Digital Network (B-ISDN); Specific intenvorking functionalities with B-ISDN. 9 TR 101 094 V1.l.l (1997-09) 3 Definitions, symbols and abbreviations 3.1 Definit ions For the purpose
41、s of the present document, the definitions given in ETSI TCR-TR 044 7 apply. 3.2 Symbols and abbreviations For the purposes of the present document, the following symbols and abbreviations apply: AAL AIS ATM B-ISDN B-ISUP CBR CDV CES DBR GPS ID IWF LAN MIB MTP N-ISDN N-ISUP OAM PBX PCM PDH PHY PRS P
42、STN PVC QOS RDI SAAL SDH SONEiT SRTS svc TDM TMN UNI vc vcc VTG ATM Adaptation Layer Alarm Indication Signal Asynchronous Transfer Mode Broadband Integrated Services Digital Network Broadband Integrated Services User Part Constant Bit Rate Cell Delay Variation Circuit Emulation Service Deterministic
43、 Bit Rate Global Positioning by Satellite Identifier Interworking Function Local Area Network Management Information Base Message Transfer Part Narrowband Integrated Services Digital Network Narrowband integrated Services User Part Operation And Maintenance Private Branch Exchange Pulse Code Modulat
44、ion Plesiochronous Digital Hierarchy Physical Layer Primary Reference Source Public Service Telephone Network Permanent Virtual Connection Quality of Service Remote Defect Indication Signalling ATM Adaptation Layer Synchronous Digital Hierarchy Synchronous Optical Network Synchronous Real Time Stamp
45、 Switched Virtual Connection Time Division Multiplex Telecommunications Management Network User Network interface Virtual Channel Virtual Channel Connection Virtual Trunk Group 10 TR 101 094 Vl.1.l (1997-09) 4 ATM trunking mechanisms This clause discusses the ATM trunking mechanisms identified for i
46、nclusion in the present document for the transport of 64 kbit/s narrowband channels across a public B-ISDN. Currently, three types of ATM trunking have been identified and these are: switched trunking; CEStrunking; trunking based on service intenvorking. For switched trunking and CES trunking, which
47、 are ail variants of network interworking, either B-ISDN signalling or TMN procedures are used in order to set up the ATM connection(s) that carry the narrowband traffic channels, depending on whether the connections are PVCs or SVCs, respectively. For switched trunking, three mechanisms are availab
48、le as identified in figure 3. Figure 3: ATM Trunking Mechanisms The three switched trunking variants are described in clause 3. Note that each variant uses a single ATM connection carrying an AAL5 cell stream for the transparent transport between n;vFs of the signalling associated with the narrowban
49、d calls. Subclause 3.2 describes the one-to-one mapping approach, in which a single 64 kbitls narrowband channel is transported across a B-ISDN in a single ATM VC. This mechanism avoids the N-ISUPB-ISUP signalling translation that is necessary for Service Intenvorking. Subclause 3.3 describes a many-to-one approach based on the mapping of multiple 64 kbit/s narrowband channels in a single ATM VC. Subclause 3.4 describes a hybrid approach based on one-to one mapping plus many-to-one mapping. Clause 4 describes trunking based on the Circuit Emulation Service (C
