The NMS ISDN stack must be in LAPD stack mode to send LAPD messages.
To send a LAPD message, the application builds an ISDN_MESSAGE structure specifying the message primitive and other data, as follows:
ISDN_MESSAGE field |
Value |
---|---|
nai |
Specifies the network access identifier (NAI) of the destination trunk. |
from_ent |
ENT_APPLI Indicates that the message is sent from the application to the stack. |
to_ent |
ENT_DL_D Indicates that the message is sent to the data link layer. |
to_sapi |
DL_SAPI_SIG |
conn_id |
1 |
code |
Specifies the primitive of the LAPD message (for example DL_EST_RQ). |
inf0, inf1, inf2, inf3, inf4 |
Reserved for internal data relay. |
data_size |
Specifies the size of the message buffer containing data associated with the message, if any. |
nfas_group |
Specifies the NFAS group number for this network access identifier (NAI). Used only if duplicate NAI values are defined. |
userid |
Not used. |
If necessary, the application also builds a message buffer containing data to send.