IrDA link access protocol (IrDA) (IrLAP)
IrDALink Access Protocol (IrLAP) is the backup protocol of the IrDA layer model, which is based on High Level Data Link Control( HDLC).
IrLAP provides secured data transmission, takes care of link establishment and disconnection, provides error detection and flow control with block acknowledgement and retry. IrLAP transmits in half- duplex and uses a token-based protocol, where one device is primary and the other is secondary.
Furthermore, quality of service( QoS) can be specified in IrLAP and it has a device identifier.