Enabling the R2 Protocol

An outbound call request sequence that results in call rejection by the remote side is illustrated in Figure 54. In this case, BSMI determines that the call has been rejected during inter-register signaling and automatically clears the call request. BSMI then provides the Host indication of the failed call attempt with the L3L4mCLEAR_REQUEST message. As in the case of call acceptance, this message contains the IISDN_R2_CALL_STATUS structure that is examined to determine the precise reason for call failure. Normally, the call has been rejected by the remote side and a status code of IISDNR2statGROUP_B_AVAILABLE is indicated with the associated Group B reason for the rejection. However, other failures are possible during abnormal operation and are indicated by other values in enumeration IISDN_R2_CALL_STATUS_CODES.

(1) L4L3mCALL_REQUEST

Host

(2) L3L4mCLEAR_REQUEST

Figure 54. Outbound Call Rejected

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Dialogic 6.2 manual L4L3mCALLREQUEST Host L3L4mCLEARREQUEST, November 358