Abstract: A communication system for using a multi-tiered registration session initiation protocol (SIP) includes: a client, a relay server and a plurality of SIP servers. The relay server is connected with the SIP servers and the client. The relay server is configured to establish a connection with the client and register with each of the SIP servers so as to select at least one of the SIP servers for direct communication with the client, thereby solving the conventional problem of incompatibilities existing between the client and SIP servers and between the SIP servers and further saving communication costs for the client in dialing various numbers.

Abstract: A communication system for using the session initiation protocol (SIP) in a network address translation (NAT) environment is provided, which includes a client, a relay server and a SIP server. The relay server is connected to the SIP server and connected to the client through a NAT server. The relay server is configured to establish connection with the client and register with the SIP server so as to allow direct communication between the client and the SIP server, thereby conducting authentication and management of the client and further solving the conventional problem of incompatibility between the SIP server and the client.

Abstract: Teleconferencing control system and method are provided for an administrator to log in a setting interface supplied in the system via any network terminal, so as to input relevant setting information comprising identification information of each teleconferencing location to be controlled, and control parameters of its teleconferencing equipment terminal, through the stored identification information of each teleconferencing location and control parameter information corresponding to the teleconferencing equipment terminal at each teleconferencing location and, to perform a control operation with respect to the teleconferencing equipment terminal of each corresponding teleconferencing location via a multi-point control unit, thereby providing centralized control for a group of teleconferencing so as to provide perfect teleconferencing service and thus increase work efficiency.

Abstract: A molding device for molding a sliding member of a slide fastener includes a first mold, a second mold movable toward or away from the first mold to close or open the molding device, at least one set of upper movable moving parts, a first upper stationary molding part detachably fixed to the first mold and a second upper stationary molding part detachably fixed to the second mold. The upper stationary molding parts are replaceable to alter the design of the holding end of a pulling tab of the slide fastener. Each set of the upper movable molding parts includes a first and a second upper movable molding part installed in the first mold, a third and a fourth upper movable molding part in the second mold.