ISDNOverviewIntegrated Digital NetworksInt. Service Digital NetworkHistoryISDN ArchitectureISDN ChannelsISDN Access InterfacesOther PRI InterfacesFunctional GroupingsSlide 11ISDN Reference PointsProtocol Reference ModelISDN Protocols at UNILAPDISDN ServicesISDN AddressingOther Addressing StructuresOther Addressing (Cont.)SummaryHomeworkRaj JainThe Ohio State University1ISDNISDNRaj JainProfessor of CIS The Ohio State UniversityColumbus, OH [email protected] slides are available at http://www.cse.ohio-state.edu/~jain/cis777-00/Raj JainThe Ohio State University2OverviewOverviewHistoryInterfaces and protocol layersReference pointsAddressingRaj JainThe Ohio State University3Integrated Digital NetworksIntegrated Digital NetworksIntegrated  Both transmission and SwitchingAccess was still analogAnalogSwitchFDMFDMAnalogSwitchFDMFDMAnalogSwitch(a) NonintegratedDigitalSwitchTDMPCMDigitalSwitchDigitalSwitch(b) IntegratedTDMPCMRaj JainThe Ohio State University4Int. Service Digital NetworkInt. Service Digital NetworkPast: IDN = Integrated Digital Network  Standardized digital techniques for switching and transmission (T1 etc)1980: ISDN  Integrated access to all services  Digital end-to-end (Digital subscriber loop)One set of interfaces for all services at multiple speedsSupports both circuit switching and packet switchingOut-of-band signaling. Sophisticated network management and maintenance using Signaling System 7 (SS7)Layered protocol architectureRaj JainThe Ohio State University5HistoryHistory1968: Study Group D set by CCITT to study digital voice1972: G.702 Integrated digital switching and transmission (IDN) concept1976: Digital switching and signaling (SS7) spec1980: G.705 - One page recommendation on ISDN1984: First set of standards in 1984. Inconsistent and incomplete.1988: Revised set of standards. Implementation feasible.1992: Additional revisionsRaj JainThe Ohio State University6ISDN ArchitectureISDN Architecturenon-switched  dedicated  PermanentTE NTISDNSwitchSubscriberorProvider>64 kbpsnonswitched>64 kbpsswitched64 kbps ckt nonswitched64 kbps ckt switchedX.25PacketswitchingFrame ModeCCSISDNSwitchUser-NetworksignalingUser-NetworksignalingNetworkSubscriberPremisesPossibly ATMRaj JainThe Ohio State University7ISDN ChannelsISDN ChannelsB: 64 kbps for data or voiceD: 16 or 64 kbps for signaling or packet switched dataH: 384 kbps (H0), 1536 kbps (H11), 1920 kbps (H12)Raj JainThe Ohio State University8Basic Rate Interface (BRI): 2B + D = 2 × 64 + 16 = 144 kbps (192 kbps total)Primary Rate Interface (PRI): For LANs or PBX23 B + D = 23 × 64 + 64 = 1.536 Mbps  T130 B+ D = 30 × 64 + 64 = 1.984 Mbps = 5H0+D = E1- 64 kbps Framing+mgmtISDN Access InterfacesISDN Access InterfacesPRIBBDBRIBBBBBDRaj JainThe Ohio State University9Other PRI InterfacesOther PRI InterfacesPRI H0: 3H0+D or 4H0 = 1.544 Mbps5H0+D = 2.048 MbpsPRI H1: One H11 in 1.544 MbpsOne H12 in 2.048 MbpsPRI for Mixture of B and H0: 0 or 1 D and any combination of B and H0, e.g., 3H0+5B+D or 3H0+6B for 1.544 MbpsRaj JainThe Ohio State University10Functional GroupingsFunctional GroupingsTerminal Equipment 1 (TE1): ISDN terminalTerminal Equipment 2 (TE2): Non-ISDN terminal, e.g., POTTerminal Adapter (TA): Allows non-ISDN devices on ISDNNetwork Termination 1 (NT1): Physical layer device. Separates user premises from phone company. Owned by user in USA. Owned by PTT in many countries.Network Termination 2 (NT2): OSI layers 2-3, e.g., PBX, LANNetwork Termination 1,2 (NT12): NT1 + NT2Raj JainThe Ohio State University11Functional GroupingsFunctional GroupingsNT1: Physical and electrical terminal of ISDN at userIsolates the user from the transmission technology of the subscriber loopLine maintenance functions such as loop back testing and monitoringBit multiplexes various B and D channelsSupports multi-drop lines  Telephone, personal computer, and alarm on one NT1NT2: Digital PBX, LAN, Terminal controllerSwitching and concentrationRaj JainThe Ohio State University12ISDN Reference PointsISDN Reference PointsRate (R): Between Non-ISDN and Terminal Adapter. Uses X or V series recommendations.System (S): Between ISDN equipment and NT2. Separates user equipment from switching equipment.Terminal (T): Between NT2 and NT1. Separates network from user.User (U): U interface not defined by ITU. Defined in North America since NT owned by user.TE1TE1TE2TE2TE1 or TE2+TATE1 or TE2+TATATANT2NT2NT1NT1NT12NT12NT2NT2NT1NT1RSTURaj JainThe Ohio State University13Protocol Reference ModelProtocol Reference ModelSimilar to OSI 7-layer modelSeparate user, control, and management planesControl = signalingManagement = network diagnosis, maintenance, and operationPhysical MediumControlUserManagement234675Raj JainThe Ohio State University14ISDN Protocols at UNIISDN Protocols at UNIControlSignalingPacketCktswitchedSemipermanentPacketSwitchedEnd-to-end user signalingQ.931LAPDI.430 basic or I.431 PrimaryApplicationPresentationSessionTransportNetworkDatalinkPhysicalX.25packetI.465/V.120 LAPBD Channel B ChannelX.25packetRaj JainThe Ohio State University15LAPDLAPDLink Access Protocol for D ChannelSimilar to HDLC and LAPBX.25 packets are transmitted in LAPD framesLAPD used for signaling messagesRaj JainThe Ohio State University16ISDN ServicesISDN ServicesSix types of servicesCircuit switched calls over a B or H channelSemi-permanent connections over a B or H channelPacket switched calls over a B or H channelPacket switched calls over a D channelFrame relay calls over a B or H channelFrame relay calls over a D channelRaj JainThe Ohio State University17ISDN AddressingISDN AddressingE.164 designed for ISDN allows up to 15 digits = Superset of E.163 for telephony (12 digits)Country code: 1 to 3 digitsNational Destination Code: Provider ID or Area codeISDN Address = ISDN number + ISDN subaddressCountryCodeNationalDestinationCodeISDNSubscriberNumberISDN Subaddress(Max 40 digits)National ISDN NumberInternational ISDN Number (max 15 digits)ISDN Address (max 55 digits)Raj JainThe Ohio State University18X.121 Data NetworksOther Addressing StructuresOther Addressing StructuresZone Network term. numberData country code National numberCountry code National significant number9Telex destination code National telex number8Initial domain