SIST ETS 300 218 E1:2003

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Integrated Services Digital Network (ISDN); Syntax-based videotex lower layer protocols for ISDN packet mode (CCITT Recommendation X.31 Case A and Case B)33.080Digitalno omrežje z integriranimi storitvami (ISDN)Integrated Services Digital Network (ISDN)ICS:Ta slovenski standard je istoveten z:ETS 300 218 Edition 1SIST ETS 300 218 E1:2003en01-december-2003SIST ETS 300 218 E1:2003SLOVENSKI
STANDARD
EUROPEANETS 300 218TELECOMMUNICATIONJanuary 1993STANDARDSource: ETSI TC-TEReference: DE/TE-01012ICS:33.020Key words:ISDN, VideotexIntegrated Services Digital Network (ISDN);Syntax-based Videotex lower layers protocols for ISDN packetmode (CCITT Recommendation X.31 Case A and Case B)ETSIEuropean 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 copyright and theforegoing restriction extend to reproduction in all media.© European Telecommunications Standards Institute 1993. All rights reserved.SIST ETS 300 218 E1:2003New presentation - see History box

Page 2ETS 300 218: January 1993Whilst 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.SIST ETS 300 218 E1:2003

Page 3ETS 300 218: January 1993ContentsForeword.71Scope.92Normative references.93Definitions and abbreviations.113.1Definitions.113.2Abbreviations.124Introduction.134.1General.134.1.1CCITT Recommendation X.31 Case A access.134.1.2CCITT Recommendation X.31 Case B, B-channel access.134.1.3CCITT Recommendation X.31 Case B, D-channel access.134.2Reference configurations.144.2.1Using access to PSPDN services (CCITT Recommendation X.31 Case A)144.2.2Using the ISDN virtual circuit service (X.31 Case B) through theB-channel or the D-channel.154.3Protocol pillars.164.3.1Using access to PSPDN services (CCITT Recommendation X.31 Case A)164.3.2Using the ISDN virtual circuit service (CCITT Recommendation X.31Case B) through the B-channel.174.3.3Using the ISDN virtual circuit service (CCITT Recommendation X.31Case B) through the D-channel.185Layer 1.185.1Basic access.185.2Primary rate access.186Access to PSPDN services (CCITT Recommendation X.31 Case A).196.1Co-ordination between B-channel and D-channel.196.1.1General.196.1.2Outgoing calls.196.1.3Incoming calls.196.1.4Clearing virtual circuits.206.1.5Error handling.206.2Layer 2 protocols.206.2.1Layer 2 protocol for the D-channel.206.2.2Layer 2 protocol for the B-channel.206.2.2.1Application rules.216.2.2.2Implementation recommendations.226.3Layer 3 protocols.226.3.1Layer 3 protocol for the D-channel.226.3.1.1The access protocol.226.3.1.2Terminal addresses.226.3.1.3Outgoing calls.226.3.1.4Incoming calls.236.3.1.5Release of the switched connection.246.3.1.6Supplementary services.256.3.2Layer 3 protocol for the B-channel.256.3.2.1Bearer Independent Service (BIS).256.3.2.2Operation over multiple B-channels.256.3.2.3DTE role.256.3.2.4Logical channels to be used.256.3.2.5Packet sizes.266.3.2.6Default packet level window size.26SIST ETS 300 218 E1:2003

Page 4ETS 300 218: January 19936.3.2.7Default throughput class.266.3.2.8D-bit.266.3.2.9Q-bit.266.3.2.10Protocol identifier.266.3.2.11Address fields.276.3.2.12Data Link Disconnection Request.276.3.2.13Optional user facilities that shall be supported.276.3.2.14Recommended optional user facilities and CCITTspecified DTE facilities.276.3.2.15Excluded
Optional user facilities.287Access to the ISDN virtual circuit service (CCITT Recommendation X.31 Case B) through theB-channel.287.1Co-ordination between B-channel and D-channel.287.1.1General.287.1.2Outgoing calls.287.1.3Incoming calls.297.1.4Clearing virtual circuits.297.1.5Error handling.297.2Layer 2 protocols.297.2.1Layer 2 protocol for the D-channel.297.2.2Layer 2 protocol for the B-channel.307.2.2.1Application rules.307.2.2.2Implementation recommendations.317.3Layer 3 protocols.317.3.1Layer 3 protocol for the D-channel.317.3.1.1The access protocol.317.3.1.2Terminal addresses.317.3.1.3Outgoing calls.317.3.1.4Incoming calls.327.3.1.5Release of the switched connection.337.3.1.6Supplementary services.337.3.2Layer 3 protocol for the B-channel.337.3.2.1Bearer Independent Service (BIS).347.3.2.2Operation over multiple B-channels.347.3.2.3DTE role.347.3.2.4Logical channels to be used.347.3.2.5Packet sizes.347.3.2.6Default packet level window size.347.3.2.7Default throughput class.347.3.2.8D-bit.347.3.2.9Q-bit.357.3.2.10Protocol identifier.357.3.2.11Address fields.357.3.2.12Data Link Disconnection Request.357.3.2.13Optional user facilities that shall be supported.357.3.2.14Recommended optional user facilities and CCITTspecified DTE facilities.367.3.2.15Excluded
optional user facilities.368Access to the ISDN virtual circuit service (CCITT Recommendation X.31 Case B) through theD-channel.368.1Layer 2 protocol.368.1.1The base Standard.368.1.2Same Connection Endpoint Suffix (CES).368.1.3Responsibility for Data Link setup.378.2Layer 3 protocols.378.2.1General.378.2.2Layer 3 ISDN signalling protocols.378.2.2.1The base standard.378.2.2.2Terminal addresses.378.2.2.3Outgoing calls.378.2.2.4Incoming calls.37SIST ETS 300 218 E1:2003

Page 5ETS 300 218: January 19938.2.2.5Release of the call.398.2.2.6Supplementary services.398.2.3Layer 3 data communication protocol.398.2.3.1Bearer Independent Service.398.2.3.2Operation over p-Data Link Connections.398.2.3.3DTE role.398.2.3.4Logical channels to be used.398.2.3.5Packet sizes.408.2.3.6Default packet level window size.408.2.3.7Default throughput class.408.2.3.8D-bit.408.2.3.9Q-bit.408.2.3.10Protocol identifier.408.2.3.11Address fields.418.2.3.12Data Link Disconnection Request.418.2.3.13Optional user facilities that shall be supported.418.2.3.14Recommended optional user facilities and CCITTspecified DTE facilities.418.2.3.15Excluded
Optional user facilities.429Conformance testing requirements.429.1General.429.1.1Types of end systems.429.1.2Type approval testing standards.429.1.3Protocol Conformance Testing Standards.439.1.4Testing configurations and environmental conditions.439.1.5Abstract test methods.449.1.6Real time aspects.449.2Testing requirements resulting from application rules for lower layer protocols.449.2.1Physical layers testing.459.2.2Out of band protocol testing.459.2.3In-band protocol testing.459.3Testing requirements related to Bearer Independent Services for ISDN syntax-basedVideotex terminals.459.4Testing requirements related to access case selection and to co-ordination functions.45Annex A (informative):ISDN lower layer communication modes for syntax-based Videotex.46Annex B (informative):Overview on communication establishment parameters.47B.1General.47B.2CCITT Recommendation X.25 packet service access.47B.2.1CCITT Recommendation X.25 packet service access parameters.47B.2.2Access of CCITT Recommendation X.25 packet services over the B-channel (CCITTRecommendation X.31 Case A or Case B).48B.2.3Access of CCITT Recommendation X.25 service over the D-channel (CCITTRecommendation X.31 Case B).48B.3Case selection for communication establishment.49B.3.1Outgoing calls.49B.3.2Incoming calls.50Annex C (informative):End-to-end system configurations.54C.1Introduction.54C.2Network configurations.54C.3Types of interfaces at the two end-systems.55C.4End system characteristics.56SIST ETS 300 218 E1:2003

Page 6ETS 300 218: January 1993Annex D (informative):Lower layer conformance testing for syntax-based Videotex.58D.1Introduction.58D.2References.58D.2.1Basic references.58D.2.2Additional references.58D.3Terminology.58D.4Elements of the test specifications.59D.4.1PICS proforma.59D.4.2PIXIT proforma.59D.4.3Test suites.59D.4.4Test case selection and parametrization.59D.4.5Test notation.60D.5Modification to PICS resulting from application rules constraining lower layer protocols.60D.5.1Out of band protocols.60D.5.1.1Layer 2 protocol.60D.5.1.2Layer 3 protocol.61D.5.2In-band protocols.62D.5.2.1Layer 2 protocol.62D.5.2.2Layer 3 protocol.63D.6Mapping of PICS related to SBV Bearer Independent services to protocol test suites.63D.7New PICS entries related to access case selection and coordination functions.63D.7.1CCITT Recommendation X.31 access case selection.64D.7.2Co-ordination between protocol pillars.65Annex E (informative):Bibliography.66History.69SIST ETS 300 218 E1:2003

Page 7ETS 300 218: January 1993ForewordThis European Telecommunication Standard (ETS) has been produced by the Terminal Equipment (TE)Technical Committee of the European Telecommunications Standards Institute (ETSI).This ETS contains five informative annexes (Annexes A to E).SIST ETS 300 218 E1:2003

Page 8ETS 300 218: January 1993Blank pageSIST ETS 300 218 E1:2003

Page 9ETS 300 218: January 19931ScopeThis ETS specifies the usage of all protocols and supplementary services up to and including layer 3 forSyntax-based Videotex (SBV) terminal equipment in the Integrated Services Digital Network (ISDN). Thescope of this ETS is limited to virtual circuits using the three different DTE/DCE modes of connection, i.e.:a)the DTE/DCE connection to Public Switched Packet Data Network (PSPDN) services(CCITT Recommendation X.31 [4], Case A);b)the ISDN virtual circuit service through the B-channel (CCITT RecommendationX.31 [4], Case B);c)the ISDN virtual circuit service through the D-channel (CCITT RecommendationX.31 [4], Case B).This ETS is applicable to terminal equipment supporting the Syntax-based Videotex using either basicaccess or primary rate access to the ISDN. In this context, a terminal equipment is either a VideotexTerminal, a Videotex Service Centre, a Videotex Access Point or a Videotex Host (cf. subclause 3.1).This ETS is based on other ETSs, International Standards or CCITT Recommendations and, wherenecessary, it adds new or other requirements as application rules.Conformance testing will be specified by reference to the individual Protocol Implementation ConformanceStatement (PICS) proformas and the Abstract Test Suites (ATS).2Normative referencesThis ETS incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text and the publications are listedhereafter. For dated references, subsequent amendments to or revisions of any of these publicationsapply to this ETS only when incorporated in it by amendment or revision. For undated references the latestedition of the publication referred to applies.[1]CCITT Recommendation F.300 (1988): "Videotex service".[2]CCITT Recommendation I.333 (1988): "Terminal selection in ISDN".[3]CCITT Recommendation X.25 (1988): "Interface between data terminalequipment (DTE) and data circuit-terminating equipment (DCE) for terminalsoperating in the packet mode and connected to public data networks bydedicated circuit".[4]CCITT Recommendation X.31 (1988): "Support of packet mode terminalequipment by an ISDN".[5]CCITT Recommendation X.32 (1988): "Interface between Data TerminalEquipment (DTE) and Data Circuit-terminating Equipment (DCE) for terminalsoperating in the packet mode and accessing a packet switched public datanetwork through a public switched telephone network or an integrated servicesdigital network or a circuit switched public data network".[6]ETS 300 007 (1991): "Integrated Services Digital Network (ISDN); Support ofpacket mode terminal equipment by an ISDN".[7]ETS 300 011 (1992): "Integrated Services Digital Network (ISDN); Primary rateuser-network interface, Layer 1 specification and test principles".[8]ETS 300 012 (1992): "Integrated Services Digital Network (ISDN); Basic user-network interface, Layer 1 specification and test principles".[9]ETS 300 102-1 (1990): "Integrated Services Digital Network (ISDN); User-network interface layer 3, Specifications for basic call control".SIST ETS 300 218 E1:2003

Page 10ETS 300 218: January 1993[10]ETS 300 104 (1990): "Integrated Services Digital Network (ISDN); Attachmentrequirements for terminal equipment to connect to an ISDN using ISDN basicaccess; Layer 3 aspects (Candidate NET 3 Part 2)".[11]ETS 300 125 (1991): "Integrated Services Digital Network (ISDN); User-networkinterface data link layer specification, Application of CCITT RecommendationsQ.920/I.440 and Q.921/I.441".[12]ETS 300 153 (1992): "Integrated Services Digital Network (ISDN); Attachmentrequirements for terminal equipment to connect to an ISDN using ISDN basicaccess (Candidate NET 3, Part 1)".[13]ETS 300 156 (1992): "Integrated Services Digital Network (ISDN); Attachmentrequirements for terminal equipment to connect to an ISDN using ISDN primaryrate access (Candidate NET 5)".[14]prETS 300 195 (1992) [pre-Public Enquiry]: "Integrated Services Digital Network(ISDN); Digital Subscriber Signalling System No. one (DSS1), Supplementaryservice interactions protocol (T/S 46-33Z)".[15]prETS 300 196 (1992): "Integrated Services Digital Network (ISDN); Genericfunctional protocol for the support of supplementary services, Digital SubscriberSignalling System No. one (DSS1) protocol".[16]ETS 300 223 (1992): "Terminal Equipment (TE); Syntax-based Videotex,Common end-to-end protocols".[17]prI-ETS 300 236: "Terminal Equipment (TE); Syntax-based Videotex Protocol;Terminal Conformance Testing".[18]ETR 018 (1991): "Integrated Services Digital Network (ISDN); Application of theBC-, HLC-, LLC- information elements by terminals supporting ISDN services".[19]ENV 41 105 (1988): "Information Systems Interconnection; Packet SwitchedData Network; Switched Access".[20]ISO 7498: "Information processing systems - Open Systems Interconnection -Basic Reference Model".[21]ISO 7776 (1986): "Information processing systems - Data communications -High-level data link control procedures - Description of the X.25 LAPB-compatible DTE data link procedures".[22]ISO 7776/DAM1 (1990): "Information processing systems - Datacommunications - High-level data link control procedures - Description of theX.25 LAPB-compatible DTE data link procedures. Draft Amendment 1:Conformance requirements; Annex A (Normative): PICS Proforma".[23]ISO/IEC 8208: "Information processing systems - Data communications - X.25Packet Layer Protocol for Data Terminal Equipment".[24]ISO/IEC 8208/Addendum 3: "Information processing systems - Datacommunications - X.25 Packet layer protocol for Data Terminal Equipment.Addendum 3: Conformance requirements; Annex C (Normative): PICSProforma".[25]ISO 8882-2 (1990): "Information technology - Telecommunications andinformation exchange between systems - X.25 DTE conformance testing part 2:data link layer test suite".[26]ISO 8882-3 (1991): "Information technology - Telecommunications andinformation exchange between systems - X.25 DTE conformance testing part 3:packet layer conformance test suite".SIST ETS 300 218 E1:2003

Page 11ETS 300 218: January 1993[27]ISO/IEC TR 9577 (1990): "Information technology - Telecommunica-tions andinformation exchange between systems - Protocol identi-fication in the OSINetwork Layer".[28]ISO/IEC TR 8509 (1987): "Information processing systems - Open SystemsInterconnection - Service conventions".3Definitions and abbreviations3.1DefinitionsFor the purposes of this ETS, the following definitions apply:Access Function: the functional entity which gives access to the Videotex Service. This entity is anintegral part of the Videotex Service.Access Network: the network which provides the link between the Terminal Function and the AccessFunction.Bearer Independent Service Access Point: point in an end system where the user of the BearerIndependent Service (BIS) accesses the service.Called BIS user: a BIS user with whom a calling BIS user wishes to establish a Network Connection.Calling BIS user: a BIS user that initiates a Network Connection establishment request.Data Circuit-terminating Equipment: see ISO/IEC 8208 [23] and CCITT Recommendation X.25 [3].Data Terminal Equipment: see ISO/IEC 8208 [23] and CCITT Recommendation X.25 [3].Host Function: the abstraction of the Videotex Applications available in a particular Videotex Service.Logical Channel: see ISO/IEC 8208 [23] and CCITT Recommendation X.25 [3].Network Connection: see OSI Reference Model ISO 7498 [20].Network Layer: see OSI Reference Model ISO 7498 [20].Network Service: see OSI Reference Model ISO 7498 [20].Packet Layer: see ISO/IEC 8208 [23] and CCITT Recommendation X.25 [3].Primitive: see Service Conventions Standard ISO/TR 8509 [28].Terminal Function: the abstraction of a functional entity which acts as a Videotex Terminal.Videotex Access Point: see CCITT Recommendation F.300 [1].Videotex Host: this term describes a computer which offers one or more applications and/or facilities. Itcan be represented through a Videotex Host Computer, an External Videotex Host or a Videotex ServiceCentre.Videotex Host Computer: see CCITT Recommendation F.300 [1].Videotex Service: see CCITT Recommendation F.300 [1].Videotex Service Centre: see CCITT Recommendation F.300 [1].NOTE:According to CCITT Recommendation F.300 [1], a Videotex Service Centre provideshost and/or access functions, i.e., it may also act as a Videotex Access Point.SIST ETS 300 218 E1:2003

Page 12ETS 300 218: January 1993Videotex Terminal: see CCITT Recommendation F.300 [1].Virtual Call: see ISO/IEC 8208 [23] and CCITT Recommendation X.25 [3].Virtual circuit: see ISO/IEC 8208 [23] and CCITT Recommendation X.25 [3].3.2AbbreviationsFor the purposes of this ETS, the following abbreviations apply:AUAccess UnitBCBearer CapabilityBISBearer Independent ServiceBRABasic Rate AccessCCITTInternational Telegraph and Telephone Consultative CommitteeCESConnection Endpoint SuffixD-bitDelivery Confirmation bitDCEData Circuit-terminating EquipmentDDIDirect Dialling InDTEData Terminal EquipmentDXEeither a DTE or a DCEETSEuropean Telecommunication StandardETSIEuropean Telecommunications Standards InstituteHLCHigh Layer CompatibilityISDNIntegrated Services Digital NetworkISOInternational Organization for StandardizationLAPBLink Access Procedure - BalancedLAPDLink Access Procedure on the D-ChannelLLCLow Layer CompatibilityM-bitMore Data bitMSNMultiple Subscriber NumberNLNetwork LayerNSNetwork ServiceOSIOpen Systems InterconnectionPABXPrivate Automatic Branch eXchangePDNPublic Data NetworkPHPacket HandlerPICSProtocol Implementation Conformance StatementPIXITProtocol Implementation eXtra Information for TestingPLPPacket Layer ProtocolPRAPrimary Rate AccessPSPDNPacket Switched Public Data NetworkPSTNPublic Switched Telephone NetworkPVCPermanent Virtual CircuitQ-bitQualifier bitSBVSyntax-Based VideotexSUBSubaddressingTPTerminal PortabilityUUSUser-to-User SignallingVCVirtual CallXIDeXchange IdentificationSIST ETS 300 218 E1:2003

Page 13ETS 300 218: January 19934Introduction4.1GeneralThe following subclauses specify the additional requirements to those as specified in ETS 300 223 [16] toprovide the Bearer Independent Service for syntax-based Videotex (SBV BIS).ISDN end-systems conforming to this ETS present protocol stacks at the S or T reference point asindicated in subclause 4.3. Only virtual circuit services are within the scope of this ETS.For outgoing calls, the requirements of subclause 7.1 in ETS 300 007 [6] shall apply.For incoming calls, the requirements of subclause 7.2 in ETS 300 007 [6] shall apply.The following subclauses consider the different cases of CCITT Recommendation X.25 [3] packet serviceaccess types (i.e., CCITT Recommendation X.31 [4] Case A, X.31 [4] Case B, B-channel or D-channel).NOTE 1:Annex A (informative) gives an overview of all the different possible communicationmodes in an ISDN.NOTE 2:Annex B (informative) summarises possibilities for accessing the CCITTRecommendation X.25 [3] packet services at the S/T reference point and gives thedifferent parameters for case selection.NOTE 3:In the following subclauses, the term "Semi-permanent" refers to both of the twoaccess types as defined in Clause 7 of ETS 300 007 [6].4.1.1CCITT Recommendation X.31 Case A accessFor the CCITT Recommendation X.31 [4] Case A "Switched" access of the B-channel, the requirementsof Clauses 5 (Layer 1) and 6 shall apply.For the CCITT Recommendation X.31 [4] Case A "Semi-permanent" access of the B-channel, therequirements of Clause 5 (Layer 1) and of subclauses 6.1.5 (error handling), 6.2.2 (Layer 2 of theB-channel) and 6.3.2 (Layer 3 of the B-channel) shall apply.4.1.2CCITT Recommendation X.31 Case B, B-channel accessFor the CCITT Recommendation X.31 [4] Case B "Switched" access of the B-channel, the requirementsof Clauses 5 (Layer 1) and 7 shall apply.For the CCITT Recommendation X.31 [4] Case B "Semi-permanent" access of the B-channel, therequirements of Clause 5 (Layer 1) and of subclauses 7.1.5 (error handling), 7.2.2 (Layer 2 of theB-channel) and 7.3.2 (Layer 3 of the B-channel) shall apply.4.1.3CCITT Recommendation X.31 Case B, D-channel accessThe requirements of Clauses 5 (Layer 1) and 8 shall apply, except that subclause 8.2.2.4 (Incoming calls)shall not be applicable if the "No notification" class is used.SIST ETS 300 218 E1:2003

Page 14ETS 300 218: January 19934.2Reference configurationsThis subclause illustrates the different scenarios as covered by this ETS. For a clarification of the resultingpossible end-to-end configurations refer to Annex C (informative).4.2.1Using access to PSPDN services (CCITT Recommendation X.31 Case A)B-channel is usedS/TCoincident S and T reference pointNTNetwork terminationETExchange terminationAUISDN access unit portsSBVTSyntax-based Videotex terminalNOTE :This figure is only an example of many possible configurations and is included as an aid to thetext describing the various interface configurations.Figure 1: Configuration based on ETS 300 007 [6] (CCITT Recommendation X.31 [4] Case A)Figure 1 illustrates the scenario for the access via an Access Unit (AU) to a PSPDN which is conceptuallynot a part of the ISDN. For a detailed description refer to ETS 300 007 [6], subclause 3.1: "Configurationwhen accessing PSPDN services (CCITT Recommendation X.31 [4] Case A)".SIST ETS 300 218 E1:2003

Page 15ETS 300 218: January 19934.2.2Using the ISDN virtual circuit service (X.31 Case B) through the B-channel or theD-channelB-channel is usedD-channel or B-channel is usedS/TCoincident S and T reference pointNTNetwork terminationETExchange terminationPHISDN packet handling functionSBVTSyntax-based Videotex terminalNOTE 1:This figure is only an example of many possible configurations and is included as an aid to thetext describing the various interface configurations.NOTE 2:For access over the D-channel, this connection is either on demand or semi-permanent. Thisfact has no relevance for the user-network procedures.NOTE 3:In some implementations, the PH belonging to the ISDN may reside physically in a node of thePSPDN. The service provided is still the ISDN virtual circuit service.Figure 2: Configuration based on ETS 300 007 [6] (CCITT Recommendation X.31 [4] Case B)Figure 2 shows the scenario for the case that a Packet Handler (PH) is an integral part of the ISDN. For adetailed description refer to ETS 300 007 [6], subclause 3.2: "Configuration for the ISDN virtual circuitservice (CCITT Recommendation X.31 [4] Case B)".SIST ETS 300 218 E1:2003

Page 16ETS 300 218: January 19934.3Protocol pillars4.3.1Using access to PSPDN services (CCITT Recommendation X.31 Case A)The protocol pillar in figure 3 is applicable for the access to PSPDN services:Coordination (NOTE 1)3BIS (NOTE 2)ETS 300 102-1 [9]ISO/IEC 8208 [23](X.25 PLP for DTE/DCE)(NOTE 3)2ETS 300 125 [11]ISO 7776 [21](X.25 LAPB for DTE/DCE)(NOTE 4)1ETS 300 011 [7]orETS 300 012 [8]LayerD-channelB-channelNOTE 1:The co-ordination function specifies the relationship between D-channel and B-channelprotocol pillars and is consistent with ETS 300 007 [6].NOTE 2:The syntax-based Videotex Bearer Independent Service (SBV BIS) is defined in Clause 11 ofETS 300 223 [16]. It covers also some aspects of the out-band signalling procedures.NOTE 3:CCITT Recommendation X.25 [3] PLP may also be taken as the base standard. However, onlyISO/IEC 8208 [23] is referred to explicitly throughout this ETS.NOTE 4:CCITT Recommendation X.25 [3] LAPB may also be taken as the base standard. However,only ISO 7776 [21] is referred to explicitly throughout this ETS.Figure 3: Protocol Pillar for the DTE/DCE connection to PSPDN services (ETS 300 007 [6] (CCITTRecommendation X.31 [4] Case A))At layer 1, ETS 300 012 [8] is used for ISDN basic access and ETS 300 011 [7] is used for ISDN primaryrate access. At layer 2, ETS 300 125 [11] provides for the LAPD Data link procedures on the D-channeland ISO 7776 [21] provides for the LAPB Data link procedures on the B-channel (additional applicationrules are given in subclause 6.2). At layer 3, ETS 300 102-1 [9] signalling procedures are used on theD-channel, and ISO/IEC 8208 [23] PLP is used in DTE/DCE operation on the B-channel (additionalapplication rules are given in subclause 6.3).The provisions of the SBV BIS as defined in Clause 11 of ETS 300 223 [16] apply with regard to themappings of the BIS primitives and parameters to and from the elements of the ISO/IEC 8208 [23] PLP.SIST ETS 300 218 E1:2003

Page 17ETS 300 218: January 19934.3.2Using the ISDN virtual circuit service (CCITT Recommendation X.31 Case B) throughthe B-channelThe protocol pillar in figure 4 is applicable for an access using ISDN virtual circuit services over theB-channel:Coordination (NOTE 1)3BIS (NOTE 2)ETS 300 102-1 [9]ISO/IEC 8208 [23](X.25 PLP for DTE/DCE)(NOTE 3)2ETS 300 125 [11]ISO 7776 [21](X.25 LAPB for DTE/DCE)(NOTE 4)1ETS 300 011 [7]orETS 300 012 [8]LayerD-channelB-channelNOTE 1:The co-ordination function specifies the relationship between D-channel and B-channelprotocol pillars and is consistent with ETS 300 007 [6].NOTE 2:The syntax-based Videotex Bearer Independent Service (SBV BIS) is defined in Clause 11 ofETS 300 223 [16]. It covers also some aspects of the out-band signalling procedures.NOTE 3:CCITT Recommendation X.25 [3] PLP may also be taken as the base standard. However, onlyISO/IEC 8208 [23] is referred to explicitly throughout this ETS.NOTE 4:CCITT Recommendation X.25 [3] LAPB may also be taken as the base standard. However,only ISO 7776 [21] is referred to explicitly throughout this ETS.Figure 4: Protocol Pillar for the DTE/DCE connection using the ISDN virtual circuit service throughthe B-channel (ETS 300 007 [6] (CCITT Recommendation X.31 [4] Case B))At layer 1, ETS 300 012 [8] is used for ISDN basic access and ETS 300 011 [7] is used for ISDN primaryrate access. At layer 2, ETS 300 125 [11] provides for the LAPD Data link procedures on the D-channeland ISO 7776 [21] provides for the LAPB Data link procedures on the B-channel (additional applicationrules are given in subclause 7.2). At layer 3, ETS 300 102-1 [9] signalling procedures are used on theD-channel, and ISO/IEC 8208 [23] PLP is used in DTE/DCE operation on the B-channel (additionalapplication rules are given in subclause 7.3).The provisions of the SBV BIS as defined in Clause 11 of ETS 300 223 [16] apply with regard to themappings of the BIS primitives and parameters to and from the elements of the ISO/IEC 8208 [23] PLP.SIST ETS 300 218 E1:2003

Page 18ETS 300 218: January 19934.3.3Using the ISDN virtual circuit service (CCITT Recommendation X.31 Case B) throughthe D-channelThe protocol pillar in figure 5 is applicable for an access using ISDN virtual circuit services over theD-channel:Coordination (NOTE 1)3BIS (NOTE 2)ETS 300 102-1 [9](NOTE 3)ISO/IEC 8208 [23](X.25 PLP for DTE/DCE)(NOTE 4)2ETS 300 125 [11]1ETS 300 011 [7]orETS 300 012 [8]LayerD-channelNOTE 1:The coordination function specifies the relationship between the two layer 3 protocol pillars andis consistent with ETS 300 007 [6].NOTE 2:The syntax-based Videotex Bearer Independent Service (SBV BIS) is defined in Clause 11 ofETS 300 223 [16]. It covers also some aspects of the out-band signalling procedures.NOTE 3:ETS 300 102-1 [9] is applicable for incoming calls.NOTE 4:CCITT Recommendation X.25 [3] PLP may also be taken as the base standard. However, onlyISO/IEC 8208 [23] is referred to explicitly throughout this ETS.Figure 5: Protocol Pillar for the DTE/DCE connection using the ISDN virtual circuit service throughthe D-channel (ETS 300 007 [6] (X.31 [4] Case B))At layer 1, ETS 300 012 [8] is used for ISDN basic access and ETS 300 011 [7] is used for ISDN primaryrate access. At layer 2, ETS 300 125 [11] provides for the LAPD Data link procedures on the D-channel(additional application rules are given in subclause 8.1). At layer 3, ISO/IEC 8208 [23] PLP is used inDTE/DCE operation (additional application rules are given in subclause 8.2.3). In addition,ETS 300 102-1 [9] is used for the notification of incoming calls (additional application rules are given insubclause 8.2.2).The provisions of the SBV BIS as defined in Clause 11 of ETS 300 223 [16] apply with regard to themappings of the BIS primitives and parameters to and from the elements of the ISO/IEC 8208 [23] PLP.5Layer 15.1Basic accessFor terminals using the basic access to an ISDN, ETS 300 012 [8] is applicable without any additional rule.5.2Primary rate accessFor terminals using the primary rate access to an ISDN, ETS 300 011 [7] is applicable without anyadditional rule.SIST ETS 300 218 E1:2003

Page 19ETS 300 218: January 19936Access to PSPDN services (CCITT Recommendation X.31 Case A)6.1Co-ordination between B-channel and D-channel6.1.1GeneralISDN Videotex end-systems supporting access to PSPDN services over the B-channel (CCITTRecommendation X.31 [4] Case A) shall use a protocol stack at the S or T reference point in accordancewith the standards as indicated in figure 3 (cf. subclause 4.3.1).One stack is used to support signalling on the D-channel for circuit switched access to the Access Unit(AU) function of the PSPDN. In the case of the semi-permanent B-channel service, this stack is null. Theother stack is used to support packet switched signalling and information transfer. The detailed protocolsare given in subclauses 6.2.2 and 6.3.2.Clause 11 in ETS 300 223 [16] provides the definition of a Bearer Independent Service for syntax-basedVideotex (SBV BIS) and the mapping of its elements to the protocol and procedures of ISO/IEC 8208 [23].Additional requirements for calls originated by or directed toward the ISDN end-system are specifiedbelow. Co-ordination is only required for switched B-channel ISDN connections between the end-systemand the AU.6.1.2Outgoing callsAdditional procedures are required if a B-channel is not already established or if an additional B-channel isneeded to support the additional traffic.The reception by layer 3 of a BIS-N-CONNECT request primitive shall first cause the ISDN D-channelsignalling procedure for demand access to be used to establish a B-channel as indicated in subclause 6.3.NOTE 1:The "Called party number" information element of the SETUP message, as defined inETS 300 102-1 [9], contains the ISDN address of the PSPDN Access Unit. Thedetermination of the contents of this information element, and its derivation from the"Called Address" parameter of the BIS-N-CONNECT primitive are a local matter.After a successful establishment of this B-channel connection, the procedures of Clause 11 inETS 300 223 [16] shall apply.NOTE 2:The ca
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