Dialogic 6.2 - Manual (Page 358)

Enabling the R2 Protocol
November 2009 358
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.
Figure 54. Outbound Call Rejected
(1) L4L3mCALL_REQUEST
Host
(2) L3L4mCLEAR_REQUEST