1、Standard ECMA-2532nd 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 16 kbit/sSub-Multiplexing.Standard ECMA-2532nd 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-253.DOC 06-09-00 09,22Private Integrated Services Net
3、work(PISN) -Mapping Functions for theEmployment of 64 kbit/s Circuit ModeConnections with 16 kbit/sSub-Multiplexing(Mapping/16).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
4、 as 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 16 kbit/s sub-
5、multiplexing.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 conse
6、nsus.Compared to the 1st Edition of Standard ECMA-253 (published by ECMA in December 1996), this 2nd Editionincorporates changes to achieve complete alignment with International Standard ISO/IEC 17310:2000(E) publishedby ISO/IEC in September 2000.Adopted as 2nd Edition of Standard ECMA-253 by the Ge
7、neral Assembly 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 Introduc
8、tion 27 Capabilities at the Q reference point 38 Mapping functions 38.1 Physical adaptation 38.1.1 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 - I
9、mplementation 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 f
10、or the utilization of scenarios in which 64 kbit/s circuit mode connections are sub-multiplexed into4 x 16 kbit/s channels for carrying inter-PINX signalling and user information.NOTE 1This Standard has been prepared to meet the specific needs of an application for a particular userorganisation. How
11、ever, it may also be applicable elsewhere. The requirements contained in this Standard willbe incorporated in any future standard specifying a more generic approach to bearer conditioning.In order to connect a Private Integrated Services Network Exchange (PINX) to another PINX, mappingfunctions are
12、required to adapt the specific interfaces at the C reference point to the application at the Qreference point. 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 informati
13、on at the Qreference point to the appropriate channels or timeslots at the C reference point.The C and Q reference 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 Interfa
14、ce, in accordance with ITU-T Rec. G.703.At the Q reference point the mapping provides a 16 kbit/s service for user channels to support the transfer ofunrestricted digital information and to support the transfer of speech, and a packet mode service for thesignalling channel. The applied mapping is a
15、static mapping, i.e. there is a fixed relationship between user andsignalling channels at the Q reference 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 inter
16、connected to form a Private Integrated ServicesNetwork (PISN) and that support signalling protocols 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 Refe
17、rences (normative)The following standards contain provisions which, through reference in this text, 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 e
18、ditions of the standards indicatedbelow.In the case of references to ECMA Standards that are aligned 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) - R
19、eference Configuration for PISNExchanges (PINX) (International Standard ISO/IEC 11579-1)ITU-T Rec. G.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 exist
20、ing interfaces (1999)ITU-T Rec. Q.920 Digital Subscriber Signalling System No. 1 (DSS1) - ISDN user-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 specifica
21、tion (1997)ITU-T Rec. Q.921 Am. 1 Amendment 1 to ITU-T Recommendation Q.921 (2000)- 2 -NOTE 2This Standard 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
22、 shall apply. Integrated Services Digital Network (ITU-T Rec. I.112) Private Integrated Services Network (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
23、.2.1.1 DQ-ChannelA channel used to convey call control information between the Q reference points of 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 us
24、ers is attached (Originating PINX orTerminating PINX) or a PINX at which signalling interworking occurs (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 pl
25、ane.4.2.4 Inter-PINX LinkA link between the Q reference points of two PINXs, comprising the totality 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 Im
26、plementation Conformance StatementIPC Inter-PINX ConnectionIPL Inter-PINX LinkISDN Integrated Services Digital NetworkLD-CELP Low-Delay Code Excited Linear PredictionMP MaPping functional groupingPINX Private Integrated Services Network ExchangePISN Private Integrated Services Network6 IntroductionT
27、his Standard specifies mapping functions for the following scenario: Dedicated 64 kbit/s circuit mode connection with 16 kbit/s sub-multiplexing.- 3 -This scenario consists of a dedicated 64 kbit/s circuit mode connection in a point-to-point configuration,and offering at the C reference point an int
28、erface with a single 64 kbit/s channel. This 64 kbit/s channel issub-multiplexed by the Mapping (MP) functional grouping into 4 x 16 kbit/s channels. Where such achannel is used for carrying speech, a speech compression function is also provided.The applied mapping is a static mapping. There is a fi
29、xed 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 3For more in
30、formation refer to ECMA TR/76 clause 7.7 Capabilities at the Q reference pointFor each instance of the Q reference point: 3 user channels (UQ); and 1 signalling channel (DQ) for carrying the inter-PINX layer 3 signalling protocolare provided. The user channels are numbered 13.For a UQ-channel the fo
31、llowing bearer capabilities shall be provided: information transfer rate: 16 kbit/s information transfer capability: speech, orunrestricted digital information user information layer 1 protocol: ITU-T Rec. G.728 16 kbit/s LD-CELP Other attributes shall be the same as at the C reference point.NOTE 4T
32、he user information layer 1 protocol is only specified as “LD-CELP“ for the case where the informationtransfer capability is “speech“. In the case where the information transfer capability is “unrestricted digitalinformation“, no user information layer 1 protocol is specified; it is an end-to-end ma
33、tter between terminalequipments attached to a PISN.NOTE 5Annex C (informative) specifies the codepoints to be used by the QSIG protocol when implementing themapping arrangements specified in this Standard.For a DQ-channel the following bearer capability shall be provided: Transfer mode: packet mode
34、Information transfer capability: unrestricted digital information 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 8.8 Mapping fu
35、nctionsThe PINX mapping functions shall meet the following requirements.8.1 Physical adaptationA PINX shall support the following physical adaptation:- 4 -8.1.1 64 kbit/s Unrestricted Digital Leased Line (D64U)Layer 1 termination shall be in accordance with the requirements of co-directional interfa
36、ces at 64 kbit/s,specified in ITU-T Rec. G.703.NOTE 6ETS 300 290 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 tr
37、ansfer capability: unrestricted digital information Information 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 16 kbit/s channels perceived at the Q reference point, according to therequirements for fix
38、ed format multiplexing specified in ITU-T Rec. I.460 ( 2.1.1).NOTE 7ITU-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
39、 in an A-law PCM bitstream. By extrapolation, this convention is also true foran LD-CELP bitstream encoded according to ITU-T Rec. G.728. For signalling information (e.g., HDLCat layer 2, QSIG at layer 3) bit 1 corresponds to the least significant bit in the octet. These conventionsare maintained by
40、 this Standard.Each 64 kbit/s IPC shall be sub-multiplexed into 4 16 kbit/s channels. Each 16 kbit/s channel shall bemapped to a pair of bit positions in the 64 kbit/s IPC as follows: The first 16 kbit/s channel shall be mapped to bit positions 1 and 2; The second 16 kbit/s channel shall be mapped t
41、o bit positions 3 and 4; The third 16 kbit/s channel shall be mapped to bit positions 5 and 6; and, The fourth 16 kbit/s channel shall be mapped to bit positions 7 and 8.8.2 Mapping MatrixThe mapping matrix provides for the bearer conditioning and mapping of channels at the Q reference pointto the c
42、hannels 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 atthe C reference point. Each channel at the Q reference point shall be mapped to a 16 kbit/s channel in the64 kbit/s i
43、nterface at the C reference point as follows: The DQ-channel shall be mapped to the first 16 kbit/s channel; UQ-channel number 1 shall be mapped to the second 16 kbit/s channel; UQ-channel number 2 shall be mapped to the third 16 kbit/s channel; and, UQ-channel number 3 shall be mapped to the fourth
44、 16 kbit/s channel.8.2.2 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.
45、 Q.921, shall not apply.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 8Annex D gives an example for the a
46、rrangement of functional groupings.NOTE 9A 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 kb
47、it/s IPC as specified 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
48、Standard shall complete 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 equip
49、ment implementer, as 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
