Abstract: There are provided a packet transfer device, a semiconductor device, and a packet transfer system, which can provide a DMZ constructed in a simple configuration. A LAN is connected to a first port. A public server is connected to a second port. A WAN is connected to a third port. A filtering section performs filtering processing according to attributes of each packet inputted via any one of the first to third ports. A routing section carries out routing processing on the packet which was not discarded by the filtering section.

Abstract: A voice packet communications system which objectively evaluates the voice quality in real time. Voice packets received from a network are input into an adjustment circuit. The adjustment circuit evens out the periods of the voice packets, detects the drop-out of voice packets, and inserts substitute packets in the voice packet sequence. Furthermore, the adjustment circuit outputs the number of voice packets that have dropped out, the number of substitute packets that have been inserted, and the number of voice packets that have accumulated inside the circuit, as quality information in each monitoring period. A decoding circuit converts the voice packets adjusted by the adjustment circuit into voice information. A judgement circuit calculates an index that indicates the communications quality of the voice packets from the quality information using a specified calculation formula.