IP TELEPHONE DEVICE

To substantially reduce discomfort given to a user due to deterioration in speech quality on an IP speech path.SOLUTION: Prior to measurement of speech quality, a speech quality measuring unit 15 accesses a time synchronization server 30 connected with an IP network NW1 and time synchronizes a standard time of the time synchronization server 30 with a local time of its own device, and then measures a transmission delay time, a fluctuation time, and a packet loss rate as speech quality of an IP speech path 31 on the basis of a transmission time included in an RTP packet transmitted at constant intervals from an opposite telephone device, a reception time based on the local time of its own device which received the RTP packet, and a sequence number of the packet.SELECTED DRAWING: Figure 1 【課題】ＩＰ通話路での通話品質の劣化により利用者に与える不快感を大幅に低減する。【解決手段】通話品質計測部１５が、通話品質の計測に先立ってＩＰ網ＮＷ１に接続されている時刻同期サーバ３０にアクセスして時刻同期サーバ３０の標準時と自装置のローカル時刻を時刻同期した後、相手電話装置から一定間隔で送信されたＲＴＰパケットに含まれる送信時刻と、ＲＴＰパケットを受信した自装置のローカル時刻に基づく受信時刻と、ＲＴＰパケットのシーケンス番号とに基づいて、ＩＰ通話路３１の通話品質として、伝送遅延時間、揺らぎ時間、およびパケット損失率を計測する。【選択図】 図１