How to remove the failure of ISDN module?
Basic mentality of failure analysis: the ST interface of ISDN needs to connect an NT equipment through a directly connected RJ45 line. But ISDN U interface only needs to insert the ISDN RJ11 plug provided by telecommunication operator directly on U interface. The ISDN misarrangement please follow from the physical layer to network layer process, gradually carries on. 1, First observe whether the ISDN physics link activates, in order to remove the failure of the cable, interface, and other out connecting equipment. 2, Observe whether L2 of D channel of ISDN, Q921 works normally, in order to remove the failure of TEI gain and D channel consultation activates. 3, Observe whether L3 of D channel of ISDN, Q931 dial up correctly, in order to remove the 3 layers calls failure of ISDN switch and configuration. 4, Observe whether L2 of B channel of ISDN, PPP consultation process is correct, in order to remove the failure of authentication type, encapsulation and password. 5, Observe whether the
