To provide a technique which is suitable for wireless relay of real-time communication packets.

A wireless access point 1 receives an RTP (real-time transport protocol) packet 6 which makes a wireless IP telephone set 3 as a destination, and stores real-time data, such as voice data, image data, etc., from an IP telephone set 2 through a LAN 4. The point extracts and stores the real-time data from a payload from the received RTP packet 6, and unifies it in the order of sequence number of the RTP packet 6. By the way, it creates integrated real-time data 7. Moreover, the wireless access point 1 monitors the congestion condition of the wireless LAN 5. When the wireless LAN 5 is not in a congestion condition, it reconstructs the RTP packet 8 which stores the integrated real-time data 7, and transmits the RTP packet 8 to the wireless IP telephone set 3 via the wireless LAN 5.