Recently, P2PTV is a popular application to deliver video streaming data over Internet network. On the overlay network, P2PTV applications create the logical links between pairs of peers considering round trip time (RTT) without physical network consideration. P2PTV packets are shared over a network without localization awareness which is the serious problem for Internet Service Providers (ISPs). The delay-insertion-based traffic localization scheme was proposed for solving this problem. However, this scheme sometimes leads the newly joining peer to download streaming traffic from a local neighbor peer which has only scarce upload bandwidth. This paper proposes a novel scheme of delay-insertion-based traffic localization in which the router estimates relay capability to each relay peer candidate and leads the newly joining peer to connect to a neighbor peer with sufficient performance for relaying video data. Parameters were evaluated for the optimized condition in the relay capability estimation process. In addition, experiments conducted on a real network show that our proposed scheme can lead the newly joining peer to avoid downloading video data from insufficient relay capability peers and maintain video quality close to normal P2PTV system while efficient traffic localization in level of Autonomous System (AS) network.