# ACU_D_CHANNEL_STATUS_IN

This topic describes:

- ACU_D_CHANNEL_STATUS_IN protocol variants

- ACU_D_CHANNEL_STATUS_IN macro descriptions and Q.931 IE

This message primitive can be returned when:

- An ACU_D_CHANNEL_STATUS_RQ primitive is sent to the stack.

- The Acu_send_d_channel_status_change bit is set in the Acu_behaviour substructure included in ISDN_PROTOCOL_PARMS_Q931CC.

This message primitive must be sent to the ACU_SAPI_MGT SAPI, rather than the ACU_SAPI. To do so, specify ACU_SAPI_MGT in the to_sapi field in the outgoing ACU_MESSAGE structure.

#### Purpose

Indicates the status of the D channel.

#### Conn_id

An allocated call.

## ACU_D_CHANNEL_STATUS_IN protocol variants

The following table lists the variants under which each macro is supported for this primitive. In this table, x indicates both NT and TE sides.

Macro | 4 E S S | E I 0 | N 1 2 | D M S | E T S I | V N 6 | H K G | A U S T E L 1 | N T T | K O R E A | T A I W A N | Q S I G | D P N S S | T 1 6 0 7
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Acu_d_channel_state | x | x | x | x | x | x | x | x | x | x | x | x | x | x
Acu_d_channel_nb |  |  |  |  |  |  |  |  |  |  |  |  | x |

## ACU_D_CHANNEL_STATUS_IN macro descriptions and Q.931 IE

Macro | Description | Q.931 IE
--- | --- | ---
Acu_d_channel_state | State of D channel: 0: OFF 1: ON | Does not map to an IE.
Acu_d_channel_nb | Equivalent to B channel number (for DPNSS only). | Does not map to an IE.