6-46 Installationand Maintenance Volume
Octel 200/300 S.4.1 PB60019−01
6.3 APPLICATION DELAYS
Application delays are timing values set in the Octel 200/300. Some of these delays are used to detect the
tone cadence that the PBX provides to the Octel 200/300. The tone cadence indicates a specific call
condition; for example, a ringback tone indicates that the called extension is ringing, and a busy tone
indicates that the called extension is busy.
When a PBX type is selected for System Parameter 3 — PBX TYPE/PBX MODEL, the default values
are set to match the tone cadence of the selected PBX. If the PBX type is not in the list provided by
System Parameter 3, select the PBX type OTHER. Because the tone-cadence values in that situation are
not known, the Octel 200/300 defaults to generic/industry-standard values; for example, a
1-second-on/3-second-off ring cadence, a 500-ms-on/500-ms-off busy cadence, and a 250-ms-on/off for a
fast-busy cadence. These values could need to be changed to work correctly with your PBX when OTHER
has been selected.
If the Octel 200/300 can already detect ringback, slow-busy, fast-busy, andif configured, double interrupted
ringback, the application delay indexes do not need to be modified. However, if the Octel 200/300 detects
an answer condition while monitoring single or double interrupted-ringback, slow-busy, or fast-busy tones,
you must modify the application-delay indexes. The application-delay indexes that can be modified are
described in the How to Modify Application Delays section in this chapter.

How Tones Are Recognized

When the Octel 200/300 screens a call, it is looking for single- or double-interrupted ringback, slow-busy,
or fast-busy tones. Toprocess the call transfer, the Octel 200/300 refers to application-delay indexes 49
through 52. These indexes show the maximum and minimum ON/OFF periods for any tone.
If the tone cadence detected does not comply with these delays, the Octel 200/300 determines that the
tone is not a single or double interrupted ringback, slow busy, or fast busy and that the call has been
answered. If this occurs, the message server completes the call transfer. In a screen display of the Print
Tone (PRT)and List Trace, an answer condition is indicated.
If the tone cadence is within the values set for delays 49 through 52, the Octel 200/300 then compares the
tone cadence with application-delay indexes 53 through 76 for single interrupted ringback, double
interrupted ringback, slow-busy and fast-busy delays, to determine what the condition is. If it does not
comply with any of these delays, it is assumed that the call has been answered and the Octel 200/300
completes the transfer. Figure 5-2 shows the sequence that the Octel 200/300 follows toscreen calls.
.If the PBX provides double interrupted ringback when an internal extension calls another internal
extension, System Parameter 26 — DOUBLE-INTERRUPTED RINGBACK, is set to YES. The
Octel 200/300 looks for a double interrupted ringback versus a single interrupted ringback when
calling an extension.