Border Media Gateway: Extending Multimedia Multicast Gateway to Support Inter-AS Conferencing

Lacking of high-quality links between different autonomous systems (AS) has become an obstacle to enable inter-AS multimedia conferencing. This paper presents the border media gateway, which constructs inter-AS data switching channels at a host with multiple network interfaces to get higher bandwidth, lower packet loss and even lower latency between different autonomous systems. The BGW runs at the application layer and establishes channels which listen on the specified interfaces, addresses and ports. The channel examines the header information of each RTP packet to determine if it should be forwarded to the other end of the channel. BGW does not modify any RTP/RTCP packets and supports prioritized forwarding to protect important media data. Experimental results show that border media gateway brings significant improvements on media quality for conferencing users from different AS.