Dialogic 6.2 사용자 설명서

ISDN Call Processing Overview

November 2009

319

Notification of incoming calls comes via a SETUP_IND message 

which contains the B-channel number the network would like to set 

the call up on. By turning on negotiation, you can specify a different 

(specific) B-channel on which to establish rather than the one 

requested by the network. In this case, a CALL PROCEEDING 

message will not get sent to the network and it is your responsibility 

to notify the network of the desired B-channel via any one of the 

following three messages: L4L3mCALL_PROCEEDING_REQUEST, 

L4L3mALERTING_REQUEST, and L4L3mCONNECT_REQUEST. 

If using more than one of these messages, you should be 

consistent on the B-channel value. 

You might want to do B-channel negotiation in situations where 

each of the channels is hard-code mapped to different locations 

depending on the type of call (data, voice, fax) received. If an 

incoming call to a channel is not the type of call that is handled by 

that (network-assigned) channel, then it must be (re)established on a 

channel that can handle the type of that call, or else the call won’t be 

handled properly. 

This feature is turned on by setting:

l43.data.enable_protocol.level3.cnfg.q931.b_chan_negot=1 

in the ENABLE_PROTOCOL message. In the case where the 

network indicates that the B-channel it is offering is non-negotiable, 

and the l43.data.enable_
protocol.level3.cnfg.q931.proc_on_exclusv

 field was set 

when the protocol was enabled, the calling process will proceed with 

a CALL PROCEEDING message being sent to the network without 

requiring you to indicate one. The network indicates that the 

B-channel it is offering is non-negotiable. The user had agreed to 

proceed by having set the proc_on_exlusv field. 

Connect Acknowledge is reported to the module but is not 

automatically reported to the host via the Bfv API. In order to 

retrieve L3L4mCONN_ACK_IND, set the field below to 1 in your 

ENABLE_PROTOCOL message:

l43.data.enable_protocol.level3.cnfg.q931.subscribe_connack=1

The stack can consider the call connected after sending the 

L4L3mCONNECT_REQUEST message or wait until it receives the 

CONNECT ACKNOWLEDGE from the network. If you do not want 

to wait for the network response, set the field below to 1 in your 

ENABLE_PROTOCOL message:

l43.data.enable_protocol.level3.cnfg.q931.no_rx_conn_ack=1