422 CHAPTER 22: ISDN C ONFIGURATION(Nippon Telegraph and Telephone Corporation) in Japan, ETSI (EuropeanTelecommunications Standards Institute) in Europe, NI (National ISDN), AT&T 5ESS,and ANSI (American National Standard Institute) in North America. Besides thedefault DSS1 ISDN protocol, the router supports the basic calling function of NTT,ETSI, ATT, ANSI, NI, NI2, and Q.SIG protocols, but does not support thesupplementary functions or network-side functions of these protocols.NI protocol used in North America is only applied to BRI interface. The ISDNnetwork uses SPID (Service Profile Identification) as the ID of different services, andthe switch provides the corresponding service to the terminal user according to theSPID. Each B channel corresponds to a SPID. Only after having employed the SPIDto perform the SPID handshake interaction, can the user proceed with normalcalling and disconnection process. Therefore, after the Q.921 establishes linksuccessfully and before the Q.931 calling processing starts, the user needs toobtain SPID to interact with the switch to perform the Layer 3 (Q.931)initialization, then he can start normal calling and disconnect process., otherwise,the calling will fail.By far, there are three ways to obtain the SPID on one BRI interface over the ISDNin North America.■ Manually input the SPID consisting of 9 to 20 digits.■ 14-digit SPID (Generic SPID Format). The former 10 digits are input by the user,and the latter 4 digits can only be “0101”.■ Allocate by SPCS (Stored Program Control Switching System) throughAutomated SPID Selection Regulation.The former two ways to obtain SPID are regarded as static configuration methods,and the third one is taken as dynamic negotiation method. If the user does notspecify a SPID in static method, the system will adopt dynamic method by default.Configuring ISDNConfiguring ISDN BRI Follow these steps to configure ISDN BRI:To do... Use the command... RemarksEnter system view system-view -Enter specified ISDN BRIinterface viewinterface interface-typeinterface-number-Configure the BRI interface tooperate in the point-to-pointmodeisdn link-mode p2p OptionalBy default, a BRI interfaceoperates in thepoint-to-multipoint mode, inwhich a BRI interface operatingon the network side can havemultiple end devices attached toit.Set ISDN protocol type isdn protocol-typeprotocolOptionalThe ISDN protocol on the BRIinterface is DSS1 protocol bydefault.
