ATM SignalingOverviewMeta-SignalingATM AddressesAddressingAddressing (Cont)Slide 7NSAP is a Misnomer!Address RegistrationConnection TypesConnection SetupConnection ReleaseConnection Release (cont)Multipoint SetupMultipoint Setup (Cont)Slide 16Message Format: Q.2931Message FormatSample Message TypesInformation Element FormatsSample Information ElementsBandwidth ContractProtocol StacksUNI 3.1 FeaturesUNI 4.0 FeaturesSummaryHomeworkRaj JainThe Ohio State University1ATM ATM SignalingSignalingRaj Jain Professor of Computer and Information ScienceThe Ohio State UniversityColumbus, OH [email protected] slides are available at:http://www.cse.ohio-state.edu/~jain/cis777-00/Raj JainThe Ohio State University2OverviewOverviewCall Endpoints: Address FormatsCall setup/releaseTraffic Contract: Bandwidth, Quality of ServiceSignaling Mechanisms: Message formatsRaj JainThe Ohio State University3Meta-SignalingMeta-SignalingUsed to setup signaling channelsAll meta-signaling messages are one cell longand have VPI/VCI = 0/1Sets up 3 types of signaling channels:Point-to-pointGeneral broadcastSelective broadcastProcedures to:Set up new signaling channelsRelease channelsVerify channelsRaj JainThe Ohio State University4ATM AddressesATM AddressesATM Forum specifies three NSAP-like address formats: DCC ATM Format, ICD ATM Format, E.164 ATM Format. NSAP = Network Service Access PointAFIEnd SystemID (6B)High-Order DSP (10B)Selector(1B)Data CountryCode (2B)E.164 Number (8 B)39End SystemID (6B)Selector (1B)International Code Designator (2B)47End SystemID (6B)Selector (1B)45End System SuppliedNot Usedin RoutingNetwork suppliedDomain Specific Part (DSP)High-Order DSP (4B)High-Order DSP (10B)Initial Domain IdRaj JainThe Ohio State University5AddressingAddressingAuthority and Format Identifier (AFI)39 = ISO DCC, 47 = British Standards Institute ICD, 45 = ITU ISDNInitial Domain Identifier (IDI). Domain Specific Part (DSP)ISDN uses E.164 numbers (up to 15 BCD digits)ATM forum extended E.164 addresses to NSAP format. E.164 number is filled with leading zeros to make 15 digits. A F16 is padded to make 8 bytes. AFI and DSP are added.Raj JainThe Ohio State University6Addressing (Cont)Addressing (Cont)End System Identifier (ESI): 48-bit IEEE MAC address. Selector is for use inside the host and is not used for routing.All ATM addresses are 20 bytes long.ATM forum removed the division of DSP into areas, etc.Private networks must support all three formats Type of Number field = UnknownNumbering Plan Indication field = ISO NSAPRaj JainThe Ohio State University7Addressing (Cont)Addressing (Cont)Public networks must support native E.164 and may optionally support three NSAP-encoded formats. For E.164:Type of Number field = International numberNumbering Plan Indication field = Recommendation E.164If only native E.164 addresses, subaddress field in signaling messages used to convey private ATM address across.One Transit network selection possible using carrier identification code field.Raj JainThe Ohio State University8NSAP is a Misnomer!NSAP is a Misnomer!NSAP = Network Service Access Point. Identifies network layer service entrySNPA = Subnetwork point of attachment. Identifies the interface to subnetworkSNPA address (or part of it) is used to carry the packet across the network.CLNP uses NSAP to deliver the packet to the right entity in the host.ATM uses NSAP-like encoding but ATM addresses identify SNPA and not NSAP.NetworkDatalinkPhysicalSNPANSAPRaj JainThe Ohio State University9Address RegistrationAddress RegistrationUser and switch register addresses using Interim Local Management Interface (ILMI) = Simple Network Management Protocol (SNMP)User SwitchColdStart TrapInitializeGetNext RequestWhat is your address?GetNext ResponseMy address is AA-...Set RequestUse prefix +1 614-...ResponseSure. Will do.Similar activities can occur in the reverse direction.Raj JainThe Ohio State University10Connection TypesConnection TypesPermanent and SwitchedPoint to pointSymmetric or asymmetric bandwidth (Uni- or bi-directional)Point-to-multipoint: Data flow in one direction only. Data replicated by network.Leaf Initiated Join (LIJ) or non-LIJRaj JainThe Ohio State University11Connection SetupConnection SetupSetupCall ProceedingSetupCall ProceedingConnectConnect AckConnectConnect AckConnectConnect AckReleaseRelease CompleteSetupCall ProceedingAcceptRejectRaj JainThe Ohio State University12Connection ReleaseConnection ReleaseReleaseRelease completeReleaseReleaseRelease completeRelease completeReleaseRelease completeRelease completeRelease completeReleaseReleaseOrRaj JainThe Ohio State University13Connection Release (cont)Connection Release (cont)ReleaseRelease completeRelease completeReleaseConnectionTerminatedRaj JainThe Ohio State University14Multipoint SetupMultipoint SetupSetupCall ProceedingSetupCall ProceedingConnectConnect AckConnectConnect AckConnectConnect AckSetupCall Proceeding221. Connect to the first party11Raj JainThe Ohio State University15Multipoint Setup (Cont)Multipoint Setup (Cont)Add PartyAdd PartyConnectConnect AckAdd Party AckAdd Party AckSetupCallProceeding222. Add the next party. The party accepts.11Raj JainThe Ohio State University16Multipoint Setup (Cont)Multipoint Setup (Cont)Add PartyAdd PartyReleaseReleaseCompleteAdd Party RejectAdd Party RejectSetupCallProceeding223. Add the next party. The party Rejects.11Raj JainThe Ohio State University17Message Format: Q.2931Message Format: Q.2931Other Information ElementsProtocol Discriminator8 7 6 5 4 3 2 10000 Lenof Call RefFlagCall Reference ValueMessage TypeMessage (Content) LengthRaj JainThe Ohio State University18Message FormatMessage FormatProtocol Discriminator (1 Byte) = Distinguishes Q.2931 messages from other messages08 = Q.931 09 = Q.2931Call reference (4 bytes) : Identifies call to which this message is related to. One user may have many calls simultaneously.Flag = 1 Message is from call reference originatorFlag = 0 Message is to call reference originatorMessage Type (2 Bytes): Many types, e.g., connect, call proceeding, setup, release, etc.Message Length (2 Bytes): Length of contentsRaj JainThe Ohio State University19Sample Message TypesSample Message TypesBits 876 Bits 54321 Type000 Call establishment messages00010 Call proceeding00111 Connect01111 Connect Ack00101 Setup01101 Setup Ack010 Call Clearing Messages01101