Description: Options controlling the behaviour of the connection. NONE : No options are specified. HDR : ALP PAD discards all data messages incoming from the network in which the constant parts of the IN Header do not match the header of the message. ALCSD : If this option is specified and the SVC goes down, then the ALC entity is shutdown. CSD : If this option is specified and the ALC entity goes down, then the associated call is cleared. FLOW : If the number of free buffers decreases to 20% of its maximum, then flow control is imposed on the receiver. It is released when the number of free buffers reaches 50% of its maximum. If the option is not set, messages received when there are no buffers available will be discarded. Note that flow control requests from X.25 are always acted upon, regardless of the setting of this option. USE_ADDR : The address in the received message is used when the message is passed to ALC, and address checking is turned off. Any combination of the above maybe specified by summing (e.g. FLOW+USE_ADDR+. . .).