Abstract: An electronic device having a judging system to facilitate an operation of the electronic device. The judging system includes a searching module for searching MAC addresses of WiFi devices in a presently working environment. A storing module stores the MAC addresses in a data base. A comparing module judges whether the present working environment is a previously encountered environment by comparing the MAC addresses for the present working environment with MAC addresses for the previously encountered environment which have been stored in the data base. A processing module has the electronic device to perform a predetermined function if the present working environment is judged as the previously encountered environment.

Abstract: In one embodiment, a method comprises creating, in a computing network, a loop-free routing topology comprising a plurality of routing arcs for reaching multicast listeners from a multicast source, each routing arc comprising a first network device as a first end of the routing arc, a second network device as a second end of the routing arc, and at least a third network device configured for receiving from each of the first and second network devices a copy of a multicast packet originated from the multicast source; and causing the multicast packet to be propagated throughout the loop-free routing topology based on the first and second ends of each routing arc forwarding the corresponding copy into the corresponding routing arc.