Abstract: A playback device is provided. The playback device includes a processor; an audio interface connected to the processor and configured to output audio; a communication interface connected to the processor and configured to communicate over a network; a memory operably connected to the processor; and instructions stored in the memory. The instructions are executable by the processor such that the playback device can receive an audio stream via a first wireless network; play back, via the audio interface, audio content based on the audio stream; while receiving the audio stream via the first wireless network, transmit an indication of availability of the audio stream; detect a request, from another playback device, to play back the audio stream; establish a second wireless network; detect that the other playback device has joined the second wireless network; and transmit the audio stream to the other playback device via the second wireless network.

Abstract: A technique for multicast switching in a distributed communication system having a plurality of cooperating modules enables a module to forward multicast packets associated with a multicast stream without using a centralized module or control logic by determining all network interfaces and remote modules associated with the multicast stream and forwarding multicast packets to only those network interfaces and remote modules associated with the multicast stream. IGMP snooping may be used to determine the network interfaces and remote modules associated with the multicast stream, and may also be used to determine host addresses, router addresses, and an IGMP version for each network interface and for each remote module. In order to generate IGMP messages, the module learns a multicast device address from received IGMP messages and uses the multicast device address to send the IGMP messages.

Abstract: An address reporting technique for reporting address information in a distributed communication environment retrieves locally owned address information from each of a number of distributed address databases, sorts the address information according to a predetermined sorting scheme, and reports the sorted address information. Each address database is maintained by one of a plurality of interconnected modules. A reporting module reports address information by retrieving locally owned address information from its address database, retrieves locally owned address information from each of the other interconnected modules, sorts the address information according to a predetermined sorting scheme, and reports the sorted address information.

Abstract: A technique for multicast switching in a distributed communication system having a plurality of cooperating modules enables a module to forward multicast packets associated with a multicast stream without using a centralized module or control logic by determining all network interfaces and remote modules associated with the multicast stream and forwarding multicast packets to only those network interfaces and remote modules associated with the multicast stream. IGMP snooping may be used to determine the network interfaces and remote modules associated with the multicast stream, and may also be used to determine host addresses, router addresses, and an IGMP version for each network interface and for each remote module. In order to generate IGMP messages, the module learns a multicast device address from received IGMP messages and uses the multicast device address to send the IGMP messages.

Abstract: A decentralized management model enables a plurality of interconnected modules to be managed and controlled as an integrated unit without requiring any one of the interconnected modules to operate as a fully centralized manager. One of the interconnected modules is configured to operate as a base module, which coordinates certain network management operations among the interconnected modules. Each of the interconnected modules is capable of sending and receiving management and control information. Each of the interconnected modules maintains a segmented management database containing network management parameters that are specific to the particular module, and also maintains a shadowed management database containing network management parameters that are common to all of the interconnected modules in the stack.

Abstract: A distributed address database management technique involves maintaining an address database by each of a number of interconnected modules. Each module maintains a number of locally owned address entries and a number of remotely owned address entries in the address database. Each module monitors the status of its locally owned address entries, maintains the locally owned address entries based upon the status, and provides the status to the other interconnected modules. Each module maintains the remotely owned address entries based upon the status received from the other interconnected modules. When a module adds a locally owned address entry to its address database, the module notifies the other interconnected modules, which in turn add a corresponding remotely owned address entry to their respective address databases.

Abstract: An address reporting technique for reporting address information in a distributed communication environment retrieves locally owned address information from each of a number of distributed address databases, sorts the address information according to a predetermined sorting scheme, and reports the sorted address information. Each address database is maintained by one of a plurality of interconnected modules. A reporting module reports address information by retrieving locally owned address information from its address database, retrieves locally owned address information from each of the other interconnected modules, sorts the address information according to a predetermined sorting scheme, and reports the sorted address information.

Abstract: An address reporting technique for reporting address information in a distributed communication environment retrieves locally owned address information from each of a number of distributed address databases, sorts the address information according to a predetermined sorting scheme, and reports the sorted address information. Each address database is maintained by one of a plurality of interconnected modules. A reporting module reports address information by retrieving locally owned address information from its address database, retrieves locally owned address information from each of the other interconnected modules, sorts the address information according to a predetermined sorting scheme, and reports the sorted address information.

Abstract: A novel optical path switching system, architecture and technique wherein light beam data traffic is to be switched by MEMS mirrors between source and destination nodes, and test ports are used to set up optical paths even before the real data traffic is propagated, with a combination of an electrical mirror-sensing feedback loop for controlling coarse mirror positioning, and an optical path power-sensing feedback loop for controlling fine adjustments in the mirror position.

Abstract: A distributed address database management technique involves maintaining an address database by each of a number of interconnected modules. Each module maintains a number of locally owned address entries and a number of remotely owned address entries in the address database. Each module monitors the status of its locally owned address entries, maintains the locally owned address entries based upon the status, and provides the status to the other interconnected modules. Each module maintains the remotely owned address entries based upon the status received from the other interconnected modules. When a module adds a locally owned address entry to its address database, the module notifies the other interconnected modules, which in turn add a corresponding remotely owned address entry to their respective address databases.

Abstract: A distributed address database management technique involves maintaining an address database by each of a number of interconnected modules. Each module maintains a number of locally owned address entries and a number of remotely owned address entries in the address database. Each module monitors the status of its locally owned address entries, maintains the locally owned address entries based upon the status, and provides the status to the other interconnected modules. Each module maintains the remotely owned address entries based upon the status received from the other interconnected modules. When a module adds a locally owned address entry to its address database, the module notifies the other interconnected modules, which in turn add a corresponding remotely owned address entry to their respective address databases.

Abstract: A decentralized management model enables a plurality of interconnected modules to be managed and controlled as an integrated unit without requiring any one of the interconnected modules to operate as a fully centralized manager. One of the interconnected modules is configured to operate as a base module, which coordinates certain network management operations among the interconnected modules. Each of the interconnected modules is capable of sending and receiving management and control information. Each of the interconnected modules maintains a segmented management database containing network management parameters that are specific to the particular module, and also maintains a shadowed management database containing network management parameters that are common to all of the interconnected modules in the stack.

Abstract: An enhanced spanning tree protocol for data communications networks having a multi-link trunk. In one embodiment, configuration messages are transmitted from boxes of the data communications network. In one embodiment, the configuration messages that are transmitted through all physical links of the same logical link, or multi-link trunk, include the same port Identifier. A network device that receives the configuration messages is therefore able to identify all of the physical links of a logical link. The enhanced spanning tree protocol according to one embodiment of the present invention considers all of the physical links of a multi-link trunk as a single logical link when identifying and removing loops in the data communications network to form a spanning tree.

Abstract: A novel optical path switching system, architecture and technique wherein light beam data traffic is to be switched by MEMS mirrors between source and destination nodes, and test ports are used to set up optical paths even before the real data traffic is propagated, with a combination of an electrical mirror-sensing feedback loop for controlling coarse mirror positioning, and an optical path power-sensing feedback loop for controlling fine adjustments in the mirror position.