Dialogic 6.2 Manuale Utente

Placing Calls on Hold Using BSMI

November 2009

210

When you invoke hold functions in BSMI, the host sends an 

L4L3mUNIVERSAL message to the board with the 
data.universal.msg_id

 field set to a value in 

, also 

detailed in Example 1. The board accepts messages from either the 

host (using an L4L3mUNIVERSAL message) and passes them to 

the network, or takes network messages and passes them to the host 

(in an L3L4mUNIVERSAL message).

Additional Informational Elements (IE) are added normally to the 

application. If sending an MT_DL_HOLD_REJ or an 

MT_DL_RETRIEVE_REJ message, add a CAUSE IE (see 

Example 2).

L3L4mUNIVERSAL messages are received with the 
data.universal.msg_id

 field set to a value from 

. If IEs 

are contained within the message 

(l34msg->data.universal.ie_count > 0), messages are 

handled normally.

#define  MT_DL_HOLD

0x24 //ITU-T Q.932 subclass 8.1

#define  MT_DL_HOLD_ACK

0x28 //ITU-T Q.932 subclass 8.1

#define  MT_DL_HOLD_REJ

0x30 //ITU-T Q.932 subclass 8.1

#define  MT_DL_RETRIEVE

0x31 //ITU-T Q.932 subclass 8.1

#define  MT_DL_RETRIEVE_ACK 0x33 //ITU-T Q.932 subclass 8.1, must contain a 

CAUSE IE

#define  MT_DL_RETRIEVE_REJ 0x37 //ITU-T Q.932 subclass 8.1, must contain a 

CAUSE IE

#define  MT_DL_STATUS

0x7D //ITU-T Q.931 subclass 84.4, not used in 

L4L3mUNIVERSAL messages