Abstract: A routing method. When implemented in a network system, the routing method ameliorates problems of media stream routing through a network address translation (NAT) device. First, whether a first terminal will correspond to different public address-and-port information for receiving media stream packets from a second terminal opposite to the first terminal after receiving different requests is determined. The first and second terminals comprise a caller and a callee which are capable of communicating in SIP protocol. The public address-and-port information is recorded as source information in media stream packets initiated by the requests. Media stream packets from the first terminal are relayed based on the determination.

Abstract: A method of detecting the type of network address translator utilizes the SIP standard structure and protocol between a user agent and a call manager; wherein after receiving a request message sent from the user agent, the call manager uses different step to reply, and then detects the network type of NAT according to the reply message sent by the user agent.

Abstract: An electronic switching device, externally connected with an alternating current power source, includes an uninterruptible voltage regulating switch for generating an energy storage electromotive force; a signal transmitter; and a remote control module connected to an electrical device, which at least has a signal controller, a voltage detector, and a power switch. The remote control module switches the power source for the electrical device, after detecting the voltage difference due to the converting between the external power source and the energy storage electromotive force, or receiving a wireless signal transmitted by a signal transmitter, so as to turn on/off the electrical device by way of remote control or manual control. The remote control module is connected in parallel to the electrical device without limiting the power efficiency of the electrical device, capable of being completely compatible with the original circuit wiring, so as to save construction space and costs.

Abstract: A method of detecting the type of network address translator utilizes the SIP standard structure and protocol between a user agent and a call manager; wherein after receiving a request message sent from the user agent, the call manager uses different step to reply, and then detects the network type of NAT according to the reply message sent by the user agent.

Abstract: A method of reducing media relay of a network address translation (NAT) apparatus involves detecting a network type of a user agent (such as a network address port translator) to determine whether the user agent is a symmetric network type; if it is, a transmitting server is still required to relay a media stream; if it is not, a SIP standard structure and its communication protocol are utilized for changing a network address and its connecting port of an ‘invite’ packet via a proxy server so that the caller and the callee will send the media stream according to the changed network address and its connecting port.

Abstract: A routing method. When implemented in a network system, the routing method ameliorates problems of media stream routing through a network address translation (NAT) device. First, whether a first terminal will correspond to different public address-and-port information for receiving media stream packets from a second terminal opposite to the first terminal after receiving different requests is determined. The first and second terminals comprise a caller and a callee which are capable of communicating in SIP protocol. The public address-and-port information is recorded as source information in media stream packets initiated by the requests. Media stream packets from the first terminal are relayed based on the determination.