Abstract: A one-way media streaming system and a corresponding method thereof are provided. The system includes a relay server, a first user device, and a second user device. The first user device and the relay server determine the format of a specialized media streaming packet by exchanging at least one Session Initiation Protocol (SIP) option message. The first user device sends the specialized media streaming packet conforming to the format through a firewall to the relay server. The second user device sends a one-way media streaming packet to the relay server. The relay server changes the destination port of the one-way media streaming packet to be the same as the source port of the specialized media streaming packet of the first user device. The relay server then relays the one-way media streaming packet through the firewall to the first user device.