Answer Supervision

The CH and CM components of Call Control manage answer supervision.

Default Implementation

By default, the CSP propagates Answer to the distant end. No Answer notification is sent to the host.

Figure 5-10 Default Answer Supervision Mode - Propagate Answer (0x00)

Customization

You can change the Answer Supervision Mode for a channel by modifying PPL Config Byte 2 of the CH component. The mode options are listed below, along with modifications of the default call flow. Each modified call flow begins at the point where A and B are connected. The variation for each mode is shown in gray.

Important! You can also use the Answer Supervision Mode Configure message to configure Answer Supervision.

Notify Host of Answer

When Answer signaling is detected from the outseized channel, Call Control informs the host with a Call Processing Event message and does not propagate Answer to the inseized port.

Important! Required Modification: You must change PPL Config Byte 2 of the CH component to 0x01.

Figure 5-11 Mode 1 - Notify Host of Answer

Host-Initiated Answer Propagation

At any time, the host can use the Generate Call Processing Event message to independently generate Answer to the inseized port. If Answer is not generated, the PSTN could unexpectedly terminate the connection.

Important! Required Modification: You must send a Generate Call Processing Event message of Answer to the CSP.

Figure 5-12 Host-Initiated Answer Propagation

Propagate Answer to Distant End and Notify Host of Answer

When Answer signaling is detected from the outseized channel, Call Control propagates Answer to the inseized channel and notifies the host with a Call Processing Event message.

Important! Required Modification: You must change PPL Config Byte 2 of the CH component to 0x02.

Figure 5-13 Mode 2 - Propagate and Notify

No Answer Supervision

When Answer signaling is detected from the outseized channel, Call Control does not propagate Answer to the inseized port and the host is not informed of the call being answered.

Important! Required Modification: You must change PPL Config Byte 2 of the CH component to 0x03.

Figure 5-14 Mode 3 - No Answer Supervision