LAPD Link Layer

Function Mapping - Major Device

Function Mapping
Connect Request Responds with lgo_EVENT_CONNECTED.
ConnectAccept Not used.
ConnectReject Not used.
Listen Waits for first I frame.
DisconnectRequest Responds with lgo_EVENT_DISCONNECTED.
DisconnectConfirm Not used.
Write Not used.
WriteSpecial Not used.
Xoff Not used.
Xon Not used.
ResetRequest Responds with lgo_EVENT_RESET_COMPLETE.
Reopen Purges buffer queues and blocks all TEIs.

Function Mapping - Virtual Circuit

Function Mapping
Connect Request Send SABME and wait for UA.
ConnectAccept Not used.
ConnectReject Not used.
Listen Not used.
DisconnectRequest Send DISC and wait for UA.
DisconnectConfirm Not used.
Write Send an I frame.
WriteSpecial Not used.
Xoff Send an RNR.
Xon Send an RR.
ResetRequest Send SABME and wait for UA.
Reopen Send DISC.

Configuration Profile - Major Device

Parameter Explanation
Maximum number of TEIs The maximum number of TEIs that can be open at the same time.
LAPD address size (2, 3 or 4) Size of the LAPD address field (in bytes).
Loopback mode? TRUE if frames will be looped back to the LAPD layer from below.

Configuration Profile - Virtual Circuit

Parameter Explanation
Is DCE? TRUE to use DCE side encoding.
SAPI SAPI number to transfer data on.
N200 - Maximum frame retries Maximum number of retries before declaring failure.
N201 - Maximum frame size Maximum frame size in bytes.
N202 - Maximum TEI request retries Not used.
Window size <1-127> Window size (modulo 128).
Maximum unacknowledged frames Maximum number of unacknowledged I frames allowed before an acknowledgement is required.
T200 - no response timer Timeout for initiating retry or declaring failure.
T201 - TEI check Not used.
T202 - TEI request Not used.
T203 - no traffic timer Timeout for initiating link intergrity check if no traffic received.
Acknowledge I frames timer Timeout for acknowledging I frames even if maximum unacknowledged frames not reached.

Ioctl Functions - Major Device

Function Explanation
Continuity Check Sends a continuity check frame (for debugging only).

Ioctl Functions - Virtual Circuit

Function Explanation
Assign TEI Assigns the TEI number. If a TEI number has already been assigned, it is released first.
Release TEI Releases any TEI previously assigned.