1、Standard ECMA-2892nd Edition - September 2000Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chPrivate Integrated Services Network(PISN) -Mapping Functions for theEmployment of 64 kbit/s Circuit Mode
2、Connections with 8 kbit/sSub-Multiplexing.Standard ECMA-2892nd Edition - September 2000Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chIW ECMA-289.DOC 06-09-00 09,22Private Integrated Services Netw
3、ork(PISN) -Mapping Functions for theEmployment of 64 kbit/s Circuit ModeConnections with 8 kbit/sSub-Multiplexing(Mapping/8).Brief HistoryThis Standard is one of a series of standards defining mapping functions in exchanges of Private Integrated ServicesNetworks. The series uses the ISDN concepts as
4、 developed by ITU-T (formerly CCITT) and is also within theframework of standards for open systems interconnection as defined by ISO/IEC.This Standard specifies mapping functions for the type of scenario where two PINXs are interconnected via a64 kbit/s circuit mode connection with 8 kbit/s sub-mult
5、iplexing.This Standard is based upon the practical experience of ECMA member companies and the results of their active andcontinuous participation in the work of ISO/IEC JTC1, ITU-T, ETSI and other international and nationalstandardization bodies. It represents a pragmatic and widely based consensus
6、.Compared to the 1st Edition of Standard ECMA-289 (published by ECMA in June 1999), this 2nd Editionincorporates changes to achieve complete alignment with International Standard ISO/IEC 17311:2000(E) publishedby ISO/IEC in September 2000.Adopted as 2nd Edition of Standard ECMA-289 by the General As
7、sembly in September 2000.- i -Table of contents1Scope 12 Conformance 13 References (normative) 14 Definitions 24.1 External definitions 24.2 Special definitions 24.2.1 Channel 24.2.2 End PINX 24.2.3 Inter-PINX Connection 24.2.4 Inter-PINX Link 24.2.5 Transit PINX 25 Abbreviations 26 Introduction 27
8、Capabilities at the Q reference point 38 Mapping functions 48.1 Physical adaptation 48.1.1 64 kbit/s Unrestricted Digital Leased Line (D64U) 48.2 Mapping Matrix 48.2.1 Channel allocation 48.2.2 Bearer Conditioning for the DQ-channel 48.2.3 Bearer Conditioning for the UQ-channels 4Annex A - Implement
9、ation Conformance Statement (ICS) Proforma 7Annex B - Bibliography 11Annex C - QSIG Protocol Codepoints 13Annex D - Example figure for Bearer Conditioning of UQ-channels 151ScopeThis Standard defines the mapping functions in exchanges of Private Integrated Services Networks (PISNs)required for the u
10、tilization of scenarios in which 64 kbit/s circuit mode connections are sub-multiplexed intoone 16 kbit/s channel for carrying inter-PINX signalling and 6 x 8 kbit/s channels for carrying inter-PINXuser information.NOTE 1This Standard has been prepared to meet the specific needs of an application fo
11、r a particular userorganisation. However, it may also be applicable elsewhere.In order to connect a Private Integrated Services Network Exchange (PINX) to another PINX, mappingfunctions are required to adapt the specific interfaces at the C reference point to the application at the Qreference point.
12、 As such, mapping functions provide for physical adaptation to the interface at the C referencepoint. Mapping functions also provide for the mapping of user channels and signalling information at the Qreference point to the appropriate channels or timeslots at the C reference point.The C and Q refer
13、ence points are defined in ECMA-133.The type of interface at the C reference point covered by this Standard is the 64 kbit/s Unrestricted DigitalLeased Line (D64U) Terminal Equipment Interface, in accordance with ITU-T Rec. G.703.At the Q reference point the mapping provides an 8 kbit/s service for
14、user channels to support the transfer ofunrestricted digital information and to support the transfer of speech, and a 16 kbit/s packet mode service forthe signalling channel. The applied mapping is a static mapping, i.e. there is a fixed relationship between userand signalling channels at the Q refe
15、rence point and the interface at the C reference point.Management functions relating to failure management are outside the scope of this Standard.This Standard is applicable to PINXs that can be interconnected to form a Private Integrated ServicesNetwork (PISN) and that support signalling protocols
16、at the Q reference point.2 ConformanceIn order to conform to this Standard, a PINX shall satisfy the requirements identified in the ImplementationConformance Statement (ICS) proforma in annex A.3 References (normative)The following standards contain provisions which, through reference in this text,
17、constitute provision of thisStandard. All standards are subject to revision, and parties to agreements based on this Standard areencouraged to investigate the possibility of applying the most recent editions of the standards indicatedbelow.In the case of references to ECMA Standards that are aligned
18、 with ISO/IEC International Standards, thenumber of the appropriate ISO/IEC International Standard is given in brackets after the ECMA reference.ECMA-133 Private Integrated Services Network (PISN) - Reference Configuration for PISNExchanges (PINX) (International Standard ISO/IEC 11579-1)ITU-T Rec. G
19、.703 Physical/electrical characteristics of hierarchical digital interfaces (1998)ITU-T Rec. I.112 Vocabulary of terms for ISDNs (1993)ITU-T Rec. I.460 Multiplexing, rate adaption and support of existing interfaces (1999)ITU-T Rec. Q.920 Digital Subscriber Signalling System No. 1 (DSS1) - ISDN user-
20、network interfacedata link layer - General aspects (1993)ITU-T Rec. Q.920 Am. 1 Amendment 1 to ITU-T Recommendation Q.920 (2000)ITU-T Rec. Q.921 ISDN user-network interface - Data link layer specification (1997)ITU-T Rec. Q.921 Am. 1 Amendment 1 to ITU-T Recommendation Q.921 (2000)- 2 -NOTE 2This St
21、andard also contains informative references. Details of these publications are given in annex B.4 Definitions4.1 External definitionsFor the purpose of this Standard the following external definitions shall apply. Integrated Services Digital Network (ITU-T Rec. I.112) Private Integrated Services Net
22、work (ECMA-133) Private Integrated Services Network Exchange (ECMA-133)4.2 Special definitions4.2.1 ChannelA means of bi-directional transmission of user or signalling information between two points.4.2.1.1 DQ-ChannelA channel used to convey call control information between the Q reference points of
23、 two peer PINXs.4.2.1.2 UQ-ChannelA channel used to convey user information between the Q reference points of two PINXs.4.2.2 End PINXIn the context of a particular call, a PINX to which one of the users is attached (Originating PINX orTerminating PINX) or a PINX at which signalling interworking occ
24、urs (Gateway PINX).4.2.3 Inter-PINX ConnectionA connection provided by an IVN between two C reference points used to transport inter-PINXinformation from the PISN control plane and/or the PISN user plane.4.2.4 Inter-PINX LinkA link between the Q reference points of two PINXs, comprising the totality
25、 of signalling transfer anduser information transfer means.4.2.5 Transit PINXIn the context of a particular call, any PINX, excluding the End PINXs, through which the call passes.5 AbbreviationsICS Implementation Conformance StatementIPC Inter-PINX ConnectionIPL Inter-PINX LinkISDN Integrated Servic
26、es Digital NetworkMP MaPping functional groupingPINX Private Integrated Services Network ExchangePISN Private Integrated Services Network6 IntroductionThis Standard specifies mapping functions for the following scenario: Dedicated 64 kbit/s circuit mode connection sub-multiplexed to provide 8 kbit/s
27、 user information channels.This scenario consists of a dedicated 64 kbit/s circuit mode connection in a point-to-point configuration, andoffering at the C reference point an interface with a single 64 kbit/s channel. This 64 kbit/s channel is sub- 3 -multiplexed by the Mapping (MP) functional groupi
28、ng into one 16 kbit/s signalling channel and 6 x 8 kbit/suser information channels.NOTE 3Where a user information channel is used for carrying speech, a speech compression function is required.This is provided by the Switching (SW) functional groupingThe applied mapping is a static mapping. There is
29、 a fixed relationship between user and signalling channels atthe Q reference point and the interface at the C reference point.Administrative actions to apply the mapping are necessary at both sides of an IPL.At the C reference point more than one instance of the interface type may exist.NOTE 4For mo
30、re information refer to ECMA TR/76 clause 7.7 Capabilities at the Q reference pointFor each instance of the Q reference point: 6 user channels (UQ); and 1 signalling channel (DQ) for carrying the inter-PINX layer 3 signalling protocolare provided. The user channels are numbered 16.For a UQ-channel t
31、he following bearer capabilities shall be provided: information transfer rate: 8 kbit/s information transfer capability: speech, orunrestricted digital information user information layer 1 protocol: See notes 5 and 6 below.Other attributes shall be the same as at the C reference point.NOTE 5In the c
32、ase where the information transfer capability indicates “speech“, the user information layer 1protocol attribute indicates the speech encoding algorithm in use (e.g., GSM 06.90 AMR-CELP, ITU-T Rec.G.723.1 A/MP-MLQ CELP, ITU-T Rec. G.729 CS-ACELP, etc.). However, since speech encoding isperformed by
33、the Switching (SW) functional grouping and not by the Mapping (MP) functional grouping (seeannex D), the specification of the speech encoding algorithm to be used is outside the scope of this Standard.See also annex C.NOTE 6In the case where the information transfer capability indicates “unrestricte
34、d digital information“, no userinformation layer 1 protocol is indicated; it is an end-to-end matter between terminal equipments attached toa PISN.For a DQ-channel the following bearer capability shall be provided: Transfer mode: packet mode Information transfer capability: unrestricted digital info
35、rmation Information transfer rate: 16 kbit/s.Other attributes shall be the same as at the C reference point.The functions to map DQand UQchannels to an inter-PINX connection (IPC) at the C reference point aredescribed in clause 8.- 4 -8 Mapping functionsThe PINX mapping functions shall meet the foll
36、owing requirements.8.1 Physical adaptationA PINX shall support the following physical adaptation:8.1.1 64 kbit/s Unrestricted Digital Leased Line (D64U)Layer 1 termination shall be in accordance with the requirements of co-directional interfaces at 64 kbit/s,specified in ITU-T Rec. G.703.NOTE 7ETS 3
37、00 290 provides additional information about this interface type.At the C reference point, the interface described in this clause provides for one IPC with the followingbearer capability: Information transfer mode: circuit mode Information transfer capability: unrestricted digital information Inform
38、ation transfer rate: 64 kbit/s.The physical adaptation part of the mapping function shall maintain a fixed relationship between a64 kbit/s IPC and the channels perceived at the Q reference point, according to the requirements forfixed format multiplexing specified in ITU-T Rec. I.460 ( 2.1.1).NOTE 8
39、ITU-T Rec. I.460 assumes bit positions in the 64 kbit/s octet are numbered from 1 to 8 with bit position 1being the first transmitted. According to CCITT Rec. G.711, bit position 1 corresponds to the mostsignificant bit of the octet in an A-law PCM bitstream. By extrapolation, this convention is als
40、o true forbitstreams encoded according to other Recommendations of the ITU-T G-series. For signallinginformation (e.g., HDLC at layer 2, QSIG at layer 3) bit 1 corresponds to the least significant bit in theoctet. These conventions are maintained by this Standard.Each 64 kbit/s IPC shall be sub-mult
41、iplexed into 1 x 16 kbit/s channel and 6 x 8 kbit/s channels.The 16 kbit/s channel shall be mapped to bit positions 1 and 2 in the 64 kbit/s IPC.Each 8 kbit/s channel (channels 1 - 6) shall be mapped respectively to a single bit from the remaining bitpositions 3 - 8 in the 64 kbit/s IPC.8.2 Mapping
42、MatrixThe mapping matrix provides for the bearer conditioning and mapping of channels at the Q reference pointto the channels provided by the physical adaptation function.8.2.1 Channel allocationA PINX shall support the mapping of a single instance of the Q reference point on to a single interface a
43、tthe C reference point. Each channel at the Q reference point shall be mapped to a channel in the 64 kbit/sinterface at the C reference point as follows: The DQ-channel shall be mapped to the 16 kbit/s channel; UQ-channels 1 - 6 shall be mapped to the 8 kbit/s channels 1 - 6 on a one for one basis.8
44、.2.2 Bearer Conditioning for the DQ-channelThe signalling carriage mechanism connection (layer 2) on a DQ-channel shall be according to thesymmetrical application in annex A of ITU-T Rec. Q.920 and annex J of ITU-T Rec. Q.921.The SM / SREJ option, defined in annex E of ITU-T Rec. Q.921, shall not ap
45、ply.At installation time one of the sides of the DQ-channel shall be designated as master and the other sideof the DQ-channel as slave.8.2.3 Bearer Conditioning for the UQ-channelsNo bearer conditioning of the UQ-channels is necessary.- 5 -NOTE 9Annex D gives an example for the arrangement of functi
46、onal groupings.NOTE 10A PINX may need to rate-adapt incoming user information to its internal channel rate to permit internalswitching and processing.For those calls in which it is acting as a Transit PINX, a PINX shall: map UQ-channels at the Outgoing side into the outgoing 64 kbit/s IPC as specifi
47、ed in 8.2.1 above; neither decompress received user information nor re-compress transmitted user information.- 6 - 7 -Annex A(normative)Implementation Conformance Statement (ICS) ProformaA.1 IntroductionThe supplier of a protocol implementation which is claimed to conform to this Standard shall comp
48、lete theImplementation Conformance Statement (ICS) proforma in A.3.A completed ICS proforma is the ICS for the implementation in question. The ICS is a statement of whichcapabilities and options have been implemented. The ICS can have a number of uses, including use: by the equipment implementer, as
49、 a check list to reduce the risk of failure to conform to the Standardthrough oversight; by the supplier and acquirer, or potential acquirer, of the implementation, as a detailed indication of thecapabilities of the implementation, stated relative to the common basis for understanding provided by theStandards ICS proforma; by the user or potential user of an implementation, as a basis for initially checking the possibility ofinterworking with another implementation. While interworking can never be guaranteed, failure tointerwork can often be predicted from i
