This object applies only to lower SAPs (service access points). Determines if this SAP subscribes to the Flow Control Parameter Negotiation facility. This allows negotiation of packet sizes and window sizes for all incoming or outgoing calls. Options; false (1): Not subscribed. Incoming calls: This SAP refuses all Incoming Call and Call Connected packets that contain the flow control facility. Outgoing calls from upper SAPs: This SAP refuses all Call Accept packets containing flow control facilities which originate from an upper SAP. Outgoing calls from lower SAPs: If the lower SAP (incoming side) subscribes to the flow control facility, then the default settings for flow control parameters (window sizes and packet sizes) at this SAP are used to replace the flow control facilities in the Call Request/Call Accepted packet. If the lower SAP (incoming side) does not subscribe to the flow control facility, then the facility settings in the Call Request/Call Accepted packet are compared against the default flow control parameters settings (window sizes and packet sizes) for this SAP. If equal the packet is routed, if not the packet is refused and the call is cleared. true (2): Subscribed. Incoming Calls: This SAP does not alter any flow control facilities found in incoming Call Request and Call Accept packets. Outgoing Calls: This SAP does not alter any flow control facilities found in outgoing Call Request and Call Accept packets. If no flow control facilities are found this SAP inserts its default settings into the Call Request or Call Accept packet. Note: An incoming/outgoing Call Request with the D-bit set implies the use of the default packet and window sizes configured at this SAP for the virtual circuit being connected. Default Value: true (2) Related Objects: x25SapRxPacketSize x25SapTxPacketSize x25SapRxWindowSize x25SapTxWindowSize Configuration Changed: administrative and operative