SIST ETS 300 103:1996
(Main)Integrated Services Digital Network (ISDN); Support of CCITT Recommendation X.21, X.21 bis and X.20 bis based Data Terminal Equipments (DTEs) by an ISDN Synchronous and asynchronous terminal adaptation functions
Integrated Services Digital Network (ISDN); Support of CCITT Recommendation X.21, X.21 bis and X.20 bis based Data Terminal Equipments (DTEs) by an ISDN Synchronous and asynchronous terminal adaptation functions
This standard covers the connection to an ISDN in a TA of: - X.21 and X.21 bis based DTE s of user classes of service 3 to 7 & 19 -X.20 based DTE s of user classes 1 and 2 and 19200 bit/s and asynchronous data rates of 600, 1200, 2400, 3600, 4800, 7200, 9600, 12000, 14400
Digitalno omrežje z integriranimi storitvami (ISDN) - Podpora ISDN za podatkovne terminalske opreme (DTE), ki temelje na priporočilih CCITT X.21, X.21 bis in X.20 bis - Funkcije sinhronih in asinhronih terminalskih prilagodilnikov
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST ETS 300 103:1996
01-GHFHPEHU-1996
'LJLWDOQRRPUHåMH]LQWHJULUDQLPLVWRULWYDPL ,6'1 3RGSRUD,6'1]DSRGDWNRYQH
WHUPLQDOVNHRSUHPH '7( NLWHPHOMHQDSULSRURþLOLK&&,77;;ELVLQ;
ELV)XQNFLMHVLQKURQLKLQDVLQKURQLKWHUPLQDOVNLKSULODJRGLOQLNRY
Integrated Services Digital Network (ISDN); Support of CCITT Recommendation X.21,
X.21 bis and X.20 bis based Data Terminal Equipments (DTEs) by an ISDN
Synchronous and asynchronous terminal adaptation functions
Ta slovenski standard je istoveten z: ETS 300 103 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST ETS 300 103:1996 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
PSIST ETS 300 103:1996
---------------------- Page: 2 ----------------------
PSIST ETS 300 103:1996
EUROPEAN ETS 300 103
TELECOMMUNICATION December 1990
STANDARD
Source: ETSI TC-SPS Reference: T/S 46-40 [CD]
ICS: 33.080
Key words: ISDN, DTE, Terminal adaption
Integrated Services Digital Network (ISDN);
Support of CCITT Recommendation X.21, X.21 bis and X.20 bis
based Data Terminal Equipments (DTEs) by an ISDN;
Synchronous and asynchronous terminal adaption functions
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright
and the foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1991. All rights reserved.
New presentation - see History box
---------------------- Page: 3 ----------------------
PSIST ETS 300 103:1996
Page 2
ETS 300 103: December 1990
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.
---------------------- Page: 4 ----------------------
PSIST ETS 300 103:1996
Page 3
ETS 300 103: December 1990
Contents
Foreword .7
Scope .9
1 Reference configurations .10
1.1 Customer access configuration .10
1.2 Network configuration .11
1.3 Interworking situation.12
2 Terminal adaption functions .13
2.1 Adaption function for DTEs conforming to X.1 user classes of service 3 to 6.13
2.1.1 Bit rate adaption functions.13
2.1.1.1 General approach.13
2.1.1.2 First step of rate adaption (RA1) of X.1 rates to the
intermediate rates of 8/16 kbit/s .13
2.1.1.2.1 Frame structure .13
2.1.1.2.2 Frame synchronization .14
2.1.1.2.3 Status bits SP, SQ, SR.14
2.1.1.2.4 Additional signalling capacity (E bit) .15
2.1.1.2.5 Data bits.16
2.1.1.2.6 Repetition strategy.16
2.1.1.3 Second step of rate adaption (RA2) .19
2.1.1.4 Framing/reframing method and user rate identification.19
2.1.1.4.1 Search for frame alignment .19
2.1.1.4.2 Alignment monitoring/recovery .20
2.1.1.4.3 Identification of intermediate bit rate.20
2.1.2 X.21/X.21bis to D-channel protocol mapping.20
2.1.2.1 D-channel protocol to X.21 mapping (see figures 8 and 9) .21
2.1.2.1.1 SETUP (from terminal adaptor to the network) .21
2.1.2.1.2 SETUP ACKNOWLEDGE/CALL PROCEEDING (from
network).22
2.1.2.1.3 ALERTING (from network) .22
2.1.2.1.4 CONNECT (from network) .22
2.1.2.1.5 SETUP (from network) .22
2.1.2.1.6 CONNECT (from terminal adaptor).23
2.1.2.1.7 CONNECT ACKNOWLEDGE (from network).23
2.1.2.1.8 RELEASE (from network).23
2.1.2.1.9 DISCONNECT (from terminal adaptor).23
2.1.2.1.10 DISCONNECT (from network) .24
2.1.2.1.11 RELEASE COMPLETE (from network).24
2.1.2.2 X.21bis (direct call), V.25 and V.25bis.24
2.1.3 Call offering procedure in a multiterminal configuration.24
2.1.4 Ready for data Alignment.30
2.1.5 Mapping of ETS 300 102-1 causes to X.21 call progress signals.32
2.1.6 Additional information for handling of exception situations .33
2.1.6.1 Call collision.33
2.1.6.1.1 Call collision at the X.21 interface.33
2.1.6.1.2 Call collision at the S/T reference point .33
2.1.6.2 No channel available .34
2.1.6.3 Premature clearing .34
2.1.6.4 No answer to outgoing SETUP.34
---------------------- Page: 5 ----------------------
PSIST ETS 300 103:1996
Page 4
ETS 300 103: December 1990
2.2 Adaption functions for DTEs conforming to X.1 user class service 7 . 34
2.2.1 Bit rate adaption functions . 34
2.2.2 X.21/X.21bis to D-channel protocol mapping . 35
2.2.3 Call offering procedure in a multiterminal configuration . 35
2.2.4 Ready for data Alignment . 35
2.2.5 Mapping of Q.931 causes to X.21 call progress signals. 35
2.2.6 Additional information for handling of exceptional situations. 35
2.3 Rate adaption functions for DTEs conforming to X.1 user class of service 19. 35
2.3.1 Rate adaption functions. 35
2.3.2 X.21/X.21bis to D-channel protocol mapping (see figures 8 and 9) . 35
2.3.2.1 SETUP (from terminal adaptor) . 35
2.3.2.2 SET-UP ACKNOWLEDGE/CALL PROCEEDING (from
network) . 36
2.3.2.3 ALERTING (from exchange). 36
2.3.2.4 CONNECT (from network). 36
2.3.2.5 SETUP (from network). 36
2.3.2.6 CONNECT (from terminal adaptor) . 37
2.3.2.7 CONNECT ACKNOWLEDGE (from network) . 37
2.3.2.8 RELEASE (from network) (multipoint configuration). 37
2.3.2.9 DISCONNECT (from terminal adaptor) . 37
2.3.2.10 DISCONNECT (from network). 37
2.3.2.11 RELEASE COMPLETE (from network) . 38
2.3.3 Call offering procedure in a multiterminal configuration . 38
2.3.4 Ready for data Alignment . 38
2.3.4.1 Entering the data transfer phase. 38
2.3.4.2 Leaving the data transfer phase . 39
2.3.5 Mapping of Q.931 causes to X.21 call progress signals. 40
2.3.6 Additional information for handling of exception situations. 40
2.4 Adaption function for DTEs conforming to X.1 user classes of service 1 and 2 or other
asynchronous user bit rates . 41
2.4.1 Rate adaption functions. 41
2.4.1.1 General approach . 41
2.4.1.2 Supported asynchronous user rates . 42
2.4.1.3 Asynchronous-to-synchronous conversion (RAO). 42
2.4.1.4 Adaption to the B-channel rate. 43
2.4.1.5 Break signal . 43
2.4.1.6 Overspeed/underspeed . 43
2.4.1.7 Parity bits . 43
2.4.2 Flow control . 43
3 Test loops . 43
Annex A (normative): Interchange circuits used in this specification. 44
1 Essential and optional interchange circuits. 44
2 Timing arrangement . 44
3 Circuit 106. 44
4 Circuit 109. 44
5 Electrical/mechanical characteristics of interchange circuits. 46
5.1 Basic ISDN user/network interface . 46
5.2 TE2/TA (DTE/DCE) interface. 46
5.2.1 Rates less than or equal to 19.2 kbit/s. 46
5.2.2 Rates greater than 19.2 kbit/s. 46
6 Fault Conditions on interchange circuits. 46
---------------------- Page: 6 ----------------------
PSIST ETS 300 103:1996
Page 5
ETS 300 103: December 1990
Annex B (normative): X.21 Terminal adaptors - Ready for data alignment procedures .47
1 General.47
2 Ready for data alignment for user rates of 600, 1200, 2400, 4800, 7200, 9600, 14400, 19200
and 48000 bit/s.48
2.1 X.21 switched circuit interface .48
2.1.1 Procedures at calling TA .48
2.1.2 Procedures at Called TA .49
2.2 X.21 Leased circuit interface .50
2.2.1 Procedures at Calling TA .50
2.2.2 Procedures at called TA.51
3 Ready for data alignment for user rates of 64 Kbit/s.52
3.1 Procedures at calling TA.52
3.2 Procedures at called TA .53
Annex C (normative): Message functional definitions and contents, applicable at the interface at the
coincident S and T reference point.65
1 Alerting .66
2 Call proceeding .67
3 Connect.68
4 Connect acknowledge.69
5 Disconnect.70
6 Information .71
7 Notify .72
8 Progress.73
9 Release .74
10 Release complete.75
11 SETUP .76
12 SETUP ACKNOWLEDGE.78
13 STATUS .79
Annex D: Asynchronous DTE TA operating sequences .80
1 TA duplex operation .80
1.1 IDLE (or Ready) state .80
1.2 Connect TA to line state.80
1.3 Data transfer state .81
1.4 Disconnect mode .82
1.5 Loss of frame synchronization .82
2 TA half-duplex operation .83
3 Automatic calling .83
---------------------- Page: 7 ----------------------
PSIST ETS 300 103:1996
Page 6
ETS 300 103: December 1990
Annex E (normative): Timer values . 84
Annex F (normative): SDL diagrams for the protocol mapping of X.21 TA's . 85
1 General. 85
2 The formal description. 85
Annex G (informative): Flow control option for Asynchronous DTE TA's . 93
1 Local flow control: TA to DTE . 93
1.1 105/106 operation . 93
1.2 X ON/X OFF operation. 93
1.3 Other methods . 93
2 End-to-end flow control: TA to TA . 93
3 Use of channel capacity. 94
4 Requirements for a TA supporting flow control . 94
Annex H (informative): Network independent clocking. 95
1 General. 95
2 Measurement of phase differences . 95
3 Positive/negative compensation . 96
4 Encoding. 97
Annex I (informative): BC, HLC and LLC information element coding examples applicable to user
specific applications. 98
1 Support of Terminal Adaptors V.110/X.30.98
1.1 Synchronous mode of operation . 98
1.1.1 Request by a calling terminal equipment. 98
1.1.2 Compatibility at the called terminal equipment . 100
1.2 Asynchronous mode of operation . 102
1.2.1 Request by a calling terminal equipment. 102
1.2.2 Compatibility at the called terminal equipment . 104
History. 106
---------------------- Page: 8 ----------------------
PSIST ETS 300 103:1996
Page 7
ETS 300 103: December 1990
Foreword
This European Telecommunications Standard (ETS) was produced by the Signalling, Protocols and
Switching (SPS) Technical Committee of the European Telecommunications Standards Institute (ETSI)
and was adopted, having passed through the ETSI standards approval procedure.
This standard is based on the following considerations:
(a) the Integrated Services Digital Network (ISDN) will offer the universal interfaces
to connect subscriber terminals according to the reference configurations
described in CCITT Recommendation I.411;
(b) during the evolution of ISDN, however, there will exist for a considerable period
DTEs conforming to CCITT Recommendations X.21, X.21bis and X.20bis which
have to be connected to the ISDN;
(c) D-channel signalling protocol is described in ETS 300 125 and ETS 300 102-1;
(d) the X.21bis DTEs are an evolution of V-series DTEs, which also provide
interworking capability with X.21 DTEs over PDN services, and which use the
network provided signal element timing and may have specific call control
features to comply with the X.21 calling protocol;
(e) the X.20bis based DTEs are an evolution of V-series DTEs, which are operating
in the asynchronous mode and which may have call control features to comply
with the X.20 calling protocol;
(f) this Standard is an application of CCITT Recommendations X.30 and V.110.
---------------------- Page: 9 ----------------------
PSIST ETS 300 103:1996
Page 8
ETS 300 103: December 1990
Blank page
---------------------- Page: 10 ----------------------
PSIST ETS 300 103:1996
Page 9
ETS 300 103: December 1990
Scope
(1) The scope of this standard covers the connection of X.21 and X.21bis based terminals of user classes
of service 3 to 7 and 19 to the ISDN operating in accordance with circuit-switched or leased circuit
services;
(2) The scope of this standard also covers the connection of X.20bis based Terminals of CCITT user
classes of service 1 and 2, and 19200 bit/s and of asynchronous data rates of 600, 1200, 2400, 3600,
4800, 7200, 9600, 12000, 14400 to the ISDN operating in accordance with circuit-switched or leased
circuit services;
(3) The reference configurations of paragraph 1 of this Standard shall apply;
(4) The terminal adaptor (TA) functions to support X.21, X.21bis and X.20bis based DTEs, including
- bit rate adaption functions,
- call establishment functions,
- mapping functions,
- ready for data alignment,
shall be performed as outlined in section 2.
(5) The scope of this standard only covers the bit rate conversion, which is caused by the connection of
existing terminals to the ISDN user/network interface, but does not cover the requirements on bit rate
conversion caused by the inter-operation of terminals with different bit rates (ISDN/CSPN interworking);
(6) This standard does not specify a particular implementation but specifies how the functions must be
implemented when they are supported by a particular Terminal Adaptor equipment.
---------------------- Page: 11 ----------------------
PSIST ETS 300 103:1996
Page 10
ETS 300 103: December 1990
1 Reference configurations
Figures 1 and 2 show examples of possible configurations and are included simply as an aid to describing
the TA functions.
1.1 Customer access configuration
For the connection of X.21, X.21bis and X.20bis based DTEs to the ISDN, figure 1 shows a possible
reference configuration.
X.21/X .21 bis /X .20 bis
TA
S
X.21/X .21 bis /X .20 bis
S
T
TA LT2 LT1 ET
S
bis bis
X.21/X .21 /X .20
TA TA
TA: Terminal adaptor
NT: Network termination
ET: Exchange termination
NOTE: The D-channel signalling protocol may operate in a point-to-multipoint fashion as described in
ETS 300 102-1.
Figure 1: Customer access configuration example
---------------------- Page: 12 ----------------------
PSIST ETS 300 103:1996
Page 11
ETS 300 103: December 1990
1.2 Network configuration
The specification of terminal adaption functions takes account of the network configuration and the end-to-
end connection types shown in figure 2 in which the associated terminal equipment TE1 and TE2 may be
involved. The TA functions are described in section 2.
TE1
IS D N
S, T
TE2 TA
TA TE2
S, T X .21/
X.21 bis /
S, T X.20 bis
X.21/
X.21 bis /
IW F
X.20 bis
DTE DTE
Circuit sw itched
pub lic
data network
or
public switched
telephone netw ork
IWF: Interworking Functions
Figure 2: Network interworking configuration example
(The IWF are outside the scope of this standard)
The terminals TE1 and TE2 are physically and logically connected to the ISDN where the call is handled.
The TA performs the necessary bit rate adaption, the signalling conversion from X.21 signalling to the D-
channel signalling and vice-versa (X.21 mapping) and ready for data alignment. Interworking with
dedicated networks, e.g. a CSPDN, will be provided on the basis of trunk lines interconnection by using
interworking functions (IWF).
The following principles shall apply:
i) The non-voice services within the ISDN should basically not diverge from what is being
developed in X-Series of CCITT Recommendations. This refers to the various aspects
concerning quality of service, user facilities, call progress signals (see e.g. X.2 and
X.96). However existing features would be enhanced and additional features would
also be developed if account were taken of the new ISDN customer capabilities (e.g.
multiterminal arrangements, user rate at 64 kbit/s, simultaneous multimedia access as
well as the possible solution for compatibility checking).
ii) Integration of X.21 based services into the ISDN is applicable to user classes of
service 3 to 7 and 19. Integration of X.20bis based services into the ISDN is applicable
to user classes of service 1 and 2, and other asynchronous user bit rates.
---------------------- Page: 13 ----------------------
PSIST ETS 300 103:1996
Page 12
ETS 300 103: December 1990
iii) Terminals TE1 and TE2 connected to an ISDN are using the ISDN numbering scheme
(see CCITT Recommendation E.164).
1.3 Interworking situation
Bearing in mind that this ETS defines the functions performed by X.21 terminal adaptors (TA X.21),
X.21bis terminal adaptors (TA X.21bis) and X.20bis terminal adaptors (TA X.20bis), the following cases of
interworking between these terminal adaptors and between these terminal adaptors and DTEs connected
to CSPDN and PSTN may appear :
a) For user class of service 3 to 7:
(1) TA X.21 TA X.21
(2) TA X.21 TA X.21bis
(3) TA X.21bis TA X.21bis
(4) TA X.21 DTE X.21
(5) TA X.21 DTE X.21bis
(6) TA X.21 V-series DTE
(7) TA X.21bis DTE X.21
(8) TA X.21bis DTE X.21bis
(9) TA X.21bis V-series DTE
b) For user class of service 19:
(10) TA X.21 TA X.21
(11) TA X.21 TA X.21bis
(12) TA X.21bis TA X.21bis
(13) TA X.21 TE1 (S/T reference point)
(14) TA X.21bis TE1 (S/T reference point)
c) For user classes of service 1 and 2, and other asynchronous user bit rates.
(15) TA X.20bis TA X.20bis
(16) TA X.20bis DTE X.20bis
(17) TA X.20bis V-series DTE
NOTE 1: This ETS is intended to cover all TA-functions necessary to allow interworking as listed
above. Currently, this ETS covers all TA-functions necessary to allow interworking
between DTEs connected to ISDN and to CSPDN with the following exceptions:
1) for X.21bis and X.20bis only, the call set-up procedure with direct call has been
explicitly covered, but other interface arrangements of X.21bis and X.20bis are not
precluded,
2) for X.21bis, the half duplex mode of operation is not specified.
This applies to all the cases listed above, where at least one X.21bis or X.20bis
terminal is involved. Alignment with the functions provided by the interworking units
may be necessary when the relevant Recommendations are available.
NOTE 2: With the interworking cases 1-17 mentioned above, the functions provided by TA
X.21bis, TA X.20bis and the functions provided by TA V.110 should be compatible.
---------------------- Page: 14 ----------------------
PSIST ETS 300 103:1996
Page 13
ETS 300 103: December 1990
2 Terminal adaption functions
The adaption functions to support X.21, X.21bis and X.20bis based DTEs can be subdivided into three
areas, namely:
- bit rate adaption function;
- mapping functions of X.21 to related D-channel call control signalling procedures ;
- ready for data alignment.
Separate TAs may be provided either for each CCITT Recommendation X.1 user class of service or for a
group of user classes of service. A universal TA may be provided for all user classes of service 3 to 7 or
19 or 1, 2, or other asynchronous user bit rates. Within this ETS only such functions are described which
refer to single rate TAs.
2.1 Adaption function for DTEs conforming to X.1 user classes of service 3 to 6
2.1.1 Bit rate adaption functions
2.1.1.1 General approach
The bit rate adaption functions within the TA
...
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.RYIntegrated Services Digital Network (ISDN); Support of CCITT Recommendation X.21, X.21 bis and X.20 bis based Data Terminal Equipments (DTEs) by an ISDN Synchronous and asynchronous terminal adaptation functions33.080Digitalno omrežje z integriranimi storitvami (ISDN)Integrated Services Digital Network (ISDN)ICS:Ta slovenski standard je istoveten z:ETS 300 103 Edition 1PSIST ETS 300 103:1996en01-oktober-1996PSIST ETS 300 103:1996SLOVENSKI
STANDARD
PSIST ETS 300 103:1996
EUROPEANETS 300 103TELECOMMUNICATIONDecember 1990STANDARDSource: ETSI TC-SPSReference: T/S 46-40 [CD]ICS:33.080Key words:ISDN, DTE, Terminal adaptionIntegrated Services Digital Network (ISDN);Support of CCITT Recommendation X.21, X.21 bis and X.20 bisbased Data Terminal Equipments (DTEs) by an ISDN;Synchronous and asynchronous terminal adaption functionsETSIEuropean Telecommunications Standards InstituteETSI SecretariatPostal address: F-06921 Sophia Antipolis CEDEX - FRANCEOffice address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCEX.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.frTel.: +33 92 94 42 00 - Fax: +33 93 65 47 16Copyright Notification: No part may be reproduced except as authorized by written permission. The copyrightand the foregoing restriction extend to reproduction in all media.© European Telecommunications Standards Institute 1991. All rights reserved.PSIST ETS 300 103:1996New presentation - see History box
Page 2ETS 300 103: December 1990Whilst every care has been taken in the preparation and publication of this document, errors in content,typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to"ETSI Editing and Committee Support Dept." at the address shown on the title page.PSIST ETS 300 103:1996
Page 3ETS 300 103: December 1990ContentsForeword.7Scope.91Reference configurations.101.1Customer access configuration.101.2Network configuration.111.3Interworking situation.122Terminal adaption functions.132.1Adaption function for DTEs conforming to X.1 user classes of service 3 to 6.132.1.1Bit rate adaption functions.132.1.1.1General approach.132.1.1.2First step of rate adaption (RA1) of X.1 rates to theintermediate rates of 8/16 kbit/s.132.1.1.2.1Frame structure.132.1.1.2.2Frame synchronization.142.1.1.2.3Status bits SP, SQ, SR.142.1.1.2.4Additional signalling capacity (E bit).152.1.1.2.5Data bits.162.1.1.2.6Repetition strategy.162.1.1.3Second step of rate adaption (RA2).192.1.1.4Framing/reframing method and user rate identification.192.1.1.4.1Search for frame alignment.192.1.1.4.2Alignment monitoring/recovery.202.1.1.4.3Identification of intermediate bit rate.202.1.2X.21/X.21bis to D-channel protocol mapping.202.1.2.1D-channel protocol to X.21 mapping (see figures 8 and 9).212.1.2.1.1SETUP (from terminal adaptor to the network).212.1.2.1.2SETUP ACKNOWLEDGE/CALL PROCEEDING (fromnetwork).222.1.2.1.3ALERTING (from network).222.1.2.1.4CONNECT (from network).222.1.2.1.5SETUP (from network).222.1.2.1.6CONNECT (from terminal adaptor).232.1.2.1.7CONNECT ACKNOWLEDGE (from network).232.1.2.1.8RELEASE (from network).232.1.2.1.9DISCONNECT (from terminal adaptor).232.1.2.1.10DISCONNECT (from network).242.1.2.1.11RELEASE COMPLETE (from network).242.1.2.2X.21bis (direct call), V.25 and V.25bis.242.1.3Call offering procedure in a multiterminal configuration.242.1.4Ready for data Alignment.302.1.5Mapping of ETS 300 102-1 causes to X.21 call progress signals.322.1.6Additional information for handling of exception situations.332.1.6.1Call collision.332.1.6.1.1Call collision at the X.21 interface.332.1.6.1.2Call collision at the S/T reference point.332.1.6.2No channel available.342.1.6.3Premature clearing.342.1.6.4No answer to outgoing SETUP.34PSIST ETS 300 103:1996
Page 4ETS 300 103: December 19902.2Adaption functions for DTEs conforming to X.1 user class service 7.342.2.1Bit rate adaption functions.342.2.2X.21/X.21bis to D-channel protocol mapping.352.2.3Call offering procedure in a multiterminal configuration.352.2.4Ready for data Alignment.352.2.5Mapping of Q.931 causes to X.21 call progress signals.352.2.6Additional information for handling of exceptional situations.352.3Rate adaption functions for DTEs conforming to X.1 user class of service 19.352.3.1Rate adaption functions.352.3.2X.21/X.21bis to D-channel protocol mapping (see figures 8 and 9).352.3.2.1SETUP (from terminal adaptor).352.3.2.2SET-UP ACKNOWLEDGE/CALL PROCEEDING (fromnetwork).362.3.2.3ALERTING (from exchange).362.3.2.4CONNECT (from network).362.3.2.5SETUP (from network).362.3.2.6CONNECT (from terminal adaptor).372.3.2.7CONNECT ACKNOWLEDGE (from network).372.3.2.8RELEASE (from network) (multipoint configuration).372.3.2.9DISCONNECT (from terminal adaptor).372.3.2.10DISCONNECT (from network).372.3.2.11RELEASE COMPLETE (from network).382.3.3Call offering procedure in a multiterminal configuration.382.3.4Ready for data Alignment.382.3.4.1Entering the data transfer phase.382.3.4.2Leaving the data transfer phase.392.3.5Mapping of Q.931 causes to X.21 call progress signals.402.3.6Additional information for handling of exception situations.402.4Adaption function for DTEs conforming to X.1 user classes of service 1 and 2 or otherasynchronous user bit rates.412.4.1Rate adaption functions.412.4.1.1General approach.412.4.1.2Supported asynchronous user rates.422.4.1.3Asynchronous-to-synchronous conversion (RAO).422.4.1.4Adaption to the B-channel rate.432.4.1.5Break signal.432.4.1.6Overspeed/underspeed.432.4.1.7Parity bits.432.4.2Flow control.433Test loops.43Annex A (normative):Interchange circuits used in this specification.441Essential and optional interchange circuits.442Timing arrangement.443Circuit 106.444Circuit 109.445Electrical/mechanical characteristics of interchange circuits.465.1Basic ISDN user/network interface.465.2TE2/TA (DTE/DCE) interface.465.2.1Rates less than or equal to 19.2 kbit/s.465.2.2Rates greater than 19.2 kbit/s.466Fault Conditions on interchange circuits.46PSIST ETS 300 103:1996
Page 5ETS 300 103: December 1990Annex B (normative):X.21 Terminal adaptors - Ready for data alignment procedures.471General.472Ready for data alignment for user rates of 600, 1200, 2400, 4800, 7200, 9600, 14400, 19200and 48000 bit/s.482.1X.21 switched circuit interface.482.1.1Procedures at calling TA.482.1.2Procedures at Called TA.492.2X.21 Leased circuit interface.502.2.1Procedures at Calling TA.502.2.2Procedures at called TA.513Ready for data alignment for user rates of 64 Kbit/s.523.1Procedures at calling TA.523.2Procedures at called TA.53Annex C (normative):Message functional definitions and contents, applicable at the interface at thecoincident S and T reference point.651Alerting.662Call proceeding.673Connect.684Connect acknowledge.695Disconnect.706Information.717Notify.728Progress.739Release.7410Release complete.7511SETUP.7612SETUP ACKNOWLEDGE.7813STATUS.79Annex D:Asynchronous DTE TA operating sequences.801TA duplex operation.801.1IDLE (or Ready) state.801.2Connect TA to line state.801.3Data transfer state.811.4Disconnect mode.821.5Loss of frame synchronization.822TA half-duplex operation.833Automatic calling.83PSIST ETS 300 103:1996
Page 6ETS 300 103: December 1990Annex E (normative):Timer values.84Annex F (normative):SDL diagrams for the protocol mapping of X.21 TA's.851General.852The formal description.85Annex G (informative):Flow control option for Asynchronous DTE TA's.931Local flow control: TA to DTE.931.1105/106 operation.931.2X ON/X OFF operation.931.3Other methods.932End-to-end flow control: TA to TA.933Use of channel capacity.944Requirements for a TA supporting flow control.94Annex H (informative):Network independent clocking.951General.952Measurement of phase differences.953Positive/negative compensation.964Encoding.97Annex I (informative):BC, HLC and LLC information element coding examples applicable to userspecific applications.981Support of Terminal Adaptors V.110/X.30.981.1Synchronous mode of operation.981.1.1Request by a calling terminal equipment.981.1.2Compatibility at the called terminal equipment.1001.2Asynchronous mode of operation.1021.2.1Request by a calling terminal equipment.1021.2.2Compatibility at the called terminal equipment.104History.106PSIST ETS 300 103:1996
Page 7ETS 300 103: December 1990ForewordThis European Telecommunications Standard (ETS) was produced by the Signalling, Protocols andSwitching (SPS) Technical Committee of the European Telecommunications Standards Institute (ETSI)and was adopted, having passed through the ETSI standards approval procedure.This standard is based on the following considerations:(a)the Integrated Services Digital Network (ISDN) will offer the universal interfacesto connect subscriber terminals according to the reference configurationsdescribed in CCITT Recommendation I.411;(b)during the evolution of ISDN, however, there will exist for a considerable periodDTEs conforming to CCITT Recommendations X.21, X.21bis and X.20bis whichhave to be connected to the ISDN;(c)D-channel signalling protocol is described in ETS 300 125 and ETS 300 102-1;(d)the X.21bis DTEs are an evolution of V-series DTEs, which also provideinterworking capability with X.21 DTEs over PDN services, and which use thenetwork provided signal element timing and may have specific call controlfeatures to comply with the X.21 calling protocol;(e)the X.20bis based DTEs are an evolution of V-series DTEs, which are operatingin the asynchronous mode and which may have call control features to complywith the X.20 calling protocol;(f)this Standard is an application of CCITT Recommendations X.30 and V.110.PSIST ETS 300 103:1996
Page 8ETS 300 103: December 1990Blank pagePSIST ETS 300 103:1996
Page 9ETS 300 103: December 1990Scope(1) The scope of this standard covers the connection of X.21 and X.21bis based terminals of user classesof service 3 to 7 and 19 to the ISDN operating in accordance with circuit-switched or leased circuitservices;(2) The scope of this standard also covers the connection of X.20bis based Terminals of CCITT userclasses of service 1 and 2, and 19200 bit/s and of asynchronous data rates of 600, 1200, 2400, 3600,4800, 7200, 9600, 12000, 14400 to the ISDN operating in accordance with circuit-switched or leasedcircuit services;(3) The reference configurations of paragraph 1 of this Standard shall apply;(4) The terminal adaptor (TA) functions to support X.21, X.21bis and X.20bis based DTEs, including-bit rate adaption functions,-call establishment functions,-mapping functions,-ready for data alignment,shall be performed as outlined in section 2.(5) The scope of this standard only covers the bit rate conversion, which is caused by the connection ofexisting terminals to the ISDN user/network interface, but does not cover the requirements on bit rateconversion caused by the inter-operation of terminals with different bit rates (ISDN/CSPN interworking);(6) This standard does not specify a particular implementation but specifies how the functions must beimplemented when they are supported by a particular Terminal Adaptor equipment.PSIST ETS 300 103:1996
Page 10ETS 300 103: December 19901Reference configurationsFigures 1 and 2 show examples of possible configurations and are included simply as an aid to describingthe TA functions.1.1Customer access configurationFor the connection of X.21, X.21bis and X.20bis based DTEs to the ISDN, figure 1 shows a possiblereference configuration.SSSTTATATALT2LT1ETX.21/X.21 bis/X.20 bisX.21/X.21 bis/X.20 bisX.21/X.21 bis/X.20 bisTATA: Terminal adaptorNT: Network terminationET: Exchange terminationNOTE:The D-channel signalling protocol may operate in a point-to-multipoint fashion as described inETS 300 102-1.Figure 1: Customer access configuration examplePSIST ETS 300 103:1996
Page 11ETS 300 103: December 19901.2Network configurationThe specification of terminal adaption functions takes account of the network configuration and the end-to-end connection types shown in figure 2 in which the associated terminal equipment TE1 and TE2 may beinvolved. The TA functions are described in section 2.X.21/X.21 bis/X.20 bisS, TS, TS, TX.21/X.21 bis/X.20 bisTE1TE2TATATE2ISDNIWFDTEDTEdata networkorpublic switchedtelephone networkCircuit switchedpublicIWF: Interworking FunctionsFigure 2: Network interworking configuration example(The IWF are outside the scope of this standard)The terminals TE1 and TE2 are physically and logically connected to the ISDN where the call is handled.The TA performs the necessary bit rate adaption, the signalling conversion from X.21 signalling to the D-channel signalling and vice-versa (X.21 mapping) and ready for data alignment. Interworking withdedicated networks, e.g. a CSPDN, will be provided on the basis of trunk lines interconnection by usinginterworking functions (IWF).The following principles shall apply:i)The non-voice services within the ISDN should basically not diverge from what is beingdeveloped in X-Series of CCITT Recommendations. This refers to the various aspectsconcerning quality of service, user facilities, call progress signals (see e.g. X.2 andX.96). However existing features would be enhanced and additional features wouldalso be developed if account were taken of the new ISDN customer capabilities (e.g.multiterminal arrangements, user rate at 64 kbit/s, simultaneous multimedia access aswell as the possible solution for compatibility checking).ii)Integration of X.21 based services into the ISDN is applicable to user classes ofservice 3 to 7 and 19. Integration of X.20bis based services into the ISDN is applicableto user classes of service 1 and 2, and other asynchronous user bit rates.PSIST ETS 300 103:1996
Page 12ETS 300 103: December 1990iii)Terminals TE1 and TE2 connected to an ISDN are using the ISDN numbering scheme(see CCITT Recommendation E.164).1.3Interworking situationBearing in mind that this ETS defines the functions performed by X.21 terminal adaptors (TA X.21),X.21bis terminal adaptors (TA X.21bis) and X.20bis terminal adaptors (TA X.20bis), the following cases ofinterworking between these terminal adaptors and between these terminal adaptors and DTEs connectedto CSPDN and PSTN may appear :a) For user class of service 3 to 7:(1) TA X.21TA X.21(2) TA X.21TA X.21bis(3) TA X.21bisTA X.21bis(4) TA X.21DTE X.21(5) TA X.21DTE X.21bis(6) TA X.21V-series DTE(7) TA X.21bisDTE X.21(8) TA X.21bisDTE X.21bis(9) TA X.21bisV-series DTEb) For user class of service 19:(10) TA X.21TA X.21(11) TA X.21TA X.21bis(12) TA X.21bisTA X.21bis(13) TA X.21TE1 (S/T reference point)(14) TA X.21bisTE1 (S/T reference point)c) For user classes of service 1 and 2, and other asynchronous user bit rates.(15) TA X.20bisTA X.20bis(16) TA X.20bisDTE X.20bis(17) TA X.20bisV-series DTENOTE 1:This ETS is intended to cover all TA-functions necessary to allow interworking as listedabove. Currently, this ETS covers all TA-functions necessary to allow interworkingbetween DTEs connected to ISDN and to CSPDN with the following exceptions:1) for X.21bis and X.20bis only, the call set-up procedure with direct call has beenexplicitly covered, but other interface arrangements of X.21bis and X.20bis are notprecluded,2) for X.21bis, the half duplex mode of operation is not specified.This applies to all the cases listed above, where at least one X.21bis or X.20bisterminal is involved. Alignment with the functions provided by the interworking unitsmay be necessary when the relevant Recommendations are available.NOTE 2:With the interworking cases 1-17 mentioned above, the functions provided by TAX.21bis, TA X.20bis and the functions provided by TA V.110 should be compatible.PSIST ETS 300 103:1996
Page 13ETS 300 103: December 19902Terminal adaption functionsThe adaption functions to support X.21, X.21bis and X.20bis based DTEs can be subdivided into threeareas, namely:- bit rate adaption function;- mapping functions of X.21 to related D-channel call control signalling procedures ;- ready for data alignment.Separate TAs may be provided either for each CCITT Recommendation X.1 user class of service or for agroup of user classes of service. A universal TA may be provided for all user classes of service 3 to 7 or19 or 1, 2, or other asynchronous user bit rates. Within this ETS only such functions are described whichrefer to single rate TAs.2.1Adaption function for DTEs conforming to X.1 user classes of service 3 to 62.1.1Bit rate adaption functions2.1.1.1General approachThe bit rate adaption functions within the TA are shown in figure 3. The function RA1 adapts the X.1 userrate to the next higher rate expressed by 2k times 8 kbit/s (where k = 0 or 1). RA2 performs a secondconversion to 64 kbit/s.X.21/X.21 bisS, TX.164 kbit/s k28 kbit/s´k28 kbit/s´TARA1RA2RStep 1Step 2Figure 3: TA bit rate adaption functions2.1.1.2First step of rate adaption (RA1) of X.1 rates to the intermediate rates of 8/16 kbit/s2.1.1.2.1Frame structureThe conversion of X.1 rates for user classes 3, 4 and 5 to 8 kbit/s, and for user class 6 to 16 kbit/s, shallbe implemented by means of the 40-bit frame structure shown in figure 4.PSIST ETS 300 103:1996
Page 14ETS 300 103: December 1990Bit number12345678Octet 0
Odd
frames -
Even frames -010E10E20E30E40E50E60E7Octet 11P1P2P3P4P5P6SQOctet 21P7P8Q1Q2Q3Q4XOctet 31Q5Q6Q7Q8R1R2SROctet 41R3R4R5R6R7R8SPNOTE:Spare bit X, if not used for the optional flow control (see paragraph 2.4.2) or for indication of thefar end synchronization loss, shall be set to 0 (see CCITT Recommendation I.463/V.110).Figure 4Figure 4 shows that in addition to the basic frame, a multiframe consisting of two basic frames isemployed. In odd frames, octet 0 contains all zeros, whilst in even frames octet 0 consists of a onefollowed by seven E bits (see section 2.1.1.2.4). The order of bit transmission of the 40-bit frame is fromleft-to-right and from top-to-bottom.2.1.1.2.2Frame synchronizationThe 17 bit frame alignment pattern consists of all 8 bits (set to zero) of octet 0 in odd frames and bit 1 (setto 1) of the following consecutive 9 octets of the 80-bit long multiframe (see also section 2.1.1.4.2). Thefirst bit of octet 0 alternates between one and zero in consecutive frames and therefore provides amultiframe synchronization bit.2.1.1.2.3Status bits SP, SQ, SRThe bits SP, SQ and SR are used to convey channel assoc
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.