User guide

68 RealCT Direct API Developer Guide
Chapter 3: T1 Networking
Handling Outbound Calls
Handling outbound calls involves the following steps:
Seize a line
Dial out
Monitor the line for answer
Process the call
Terminate the call
Seizing a Line
Seize an idle line using either RHT_SEIZE_LINE or
RHT_OFF_HOOK. These functions are interchangeable, so all
discussion of RHT_SEIZE_LINE also applies to
RHT_OFF_HOOK.
RHT_SEIZE_LINE transmits the line seize signal and waits for
an acknowledgment from the remote end for a time defined by
RDG_REMOTE_ACK_TIMEOUT. It then waits for a time
determined by RDG_LOCAL_SEIZE_GUARD_TIME and
returns. If RHT_SEIZE_LINE does not receive an
acknowledgment, it returns the hook to idle and returns an
error. Table 16 shows the sequence of seizing a line.
Table 16. RHT_SEIZE_LINE Sequence
Action Duration
Transmit line seize
Wait for acknowledgment RDG_REMOTE_ACK_TIMEOUT
Wait RDG_LOCAL_SEIZE_GUARD_TIME
Return