Dialogic 6.2 - Manual (Page 329)

Using the overlap_rcv feature of L4L3mENABLE_PROTOCOL
November 2009 329
BSMI Reference Notes
Support for Overlap Receive mode are enabled using the overlap_rcv
flag in the BSMI_Q931_CNFG structure of L4L3mENABLE_
PROTOCOL messages.
If the Host application expects to support Overlap Receive calling
models (more typical of E1 and EURO-based BRI installations than
domestic T1 installations), it should set the overlap_rcv flag to “1”
when enabling the Q.931 D-channel. Example:
L4_to_L3_struct l43msg;
memset (&l43msg, 0, sizeof(l43msg));
l43msg.lapdid = 0;
l43msg.msgtype = L4L3mENABLE_PROTOCOL;
l43msg.data.enable_protocol.level1.l1_mode = IISDNl1modHDLC;
l43msg.data.enable_protocol.level2.l2_mode = IISDNl2modLAP_D;
l43msg.data.enable_protocol.level2.dce_dte = IISDNdirUSER_SIDE;
l43msg.data.enable_protocol.level3.l3_mode = IISDNl3modQ931;
l43msg.data.enable_protocol.level3.cnfg.q931.switch_type =
IISDNstUNKNOWN;
l43msg.data.enable_protocol.level3.cnfg.q931.variant = IISDNvarCCITT;
l43msg.data.enable_protocol.level3.cnfg.q931.overlap_rcv = 1;
BSMIControlWrite (fd, l43msg);