Abstract: Various teachings include methods and/or BACnet network systems to extend BACnet network systems for building automation systems to scale up to large topologies. The BACnet network system comprises a network of BACnet devices organized as a virtual hub-and-spoke network. One of the BACnet devices is implemented as a directed hub-device to which all other BACnet devices are connected as node-devices by using WebSocket connections. The directed hub-device is configured to limit the broadcast distribution of broadcast messages from a downlink-connection to each uplink-connection, and not to any other downlink-connection. The directed hub-device is configured to block or forward unicast messages from one downlink-connection to another downlink-connection.

Abstract: The present disclosure relates generally to the technical field of building management systems or building automation systems comprising a plurality of building devices, e.g. BACnet devices. In some embodiments, a method for providing network communication between BACnet devices via the Internet may include: initiating an outbound HTTPS connection to a pre-defined URL locating a communication web service, by a building automation BACnet device (a node of a local building automation network); and initiating an outbound HTTPS connection to the pre-defined URL locating the communication web service, by a BACnet tool. The building automation BACnet device serves as a gateway device for further BACnet devices of said local building automation network.

Abstract: The Specific service instances are requested by a client via a client application. The request is received by a Domain Name System (DNS). The request is resolved by the DNS by determining from information recorded in a DNS system memory and conveyed in the request, a first type T1 of service and a first list L1 of service instances associated with the first type T1. The DNS then searches for a linked structure in a TXT resource record for the first type T1. The linked structure identifies another list L2 of service instances associated with a subtype T2 of service. Then iteratively, for i=2, . . . , N+1, N being a number of the subtypes of service associated with the first type T1 of service, searching a TXT resource record for a linked structure identifying a corresponding subtype Ti of service and identifying a list Li+1 of service instances associated with the subtype Ti+1.

Abstract: A private key and a public key are provided during manufacture of a device and are stored in the device. At least one cryptographic key is subsequently negotiated, the negotiation being security-protected as a function of the generated private key and/or the public key. This method can find application in building automation.

Abstract: The Specific service instances are requested by a client via a client application. The request is received by a Domain Name System (DNS). The request is resolved by the DNS by determining from information recorded in a DNS system memory and conveyed in the request, a first type T1 of service and a first list L1 of service instances associated with the first type T1. The DNS then searches for a linked structure in a TXT resource record for the first type T1. The linked structure identifies another list L2 of service instances associated with a subtype T2 of service. Then iteratively, for i=2, . . . , N+1, N being the subtypes of service associated with the first type T1 of service, searching a TXT resource record for a linked structure identifying a corresponding subtype Ti of service and identifying a list Li+1 of service instances associated with the subtype Ti+1.

Abstract: A private key and a public key are provided during manufacture of a device and are stored in the device. At least one cryptographic key is subsequently negotiated, the negotiation being security-protected as a function of the generated private key and/or the public key. This method can find application in building automation.