An Overlay Architecture of Global Inter-Data Center Networking for Fast Content Delivery

Content Delivery Network services has begun being provided for fast data delivery in cloud services, but their edge-based delivery from caches is only effective for frequently accessed data. In this paper, we present an overlay network architecture for fast content delivery, which is especially effective for long tail contents. To maximize data transfer throughputs of individual overlay paths (OPs) from an origin to each other data centers (DCs), a directed maximum-bottleneck tree is first constructed based on RTT measurements between every DC pairs. Furthermore, to enhance throughput of progressive download video, the same number of multiple parallel HTTP connections are established at each hop of the OP. In a content server (CS), an uploaded video file is segmented into blocks to make up multiple sub-streams that are to be sent over their respective connections. To enable this traffic pattern by efficient routing and forwarding in such an overlay network that connects multiple DCs where standard HTTP proxy servers (PSs) are clustered to achieve scalability, name-based routing of a request for resolution from each sub-stream name to a PS address and subsequent address-based forwarding of a block request are performed at each hop in the reverse direction of the OP. For this purpose, the blocks generated in the CS are then named with a sub-stream domain that includes the origin-DC name. Numerical examples based on monitoring multiple traceroute servers located in an Asia-Pacific region show that throughput estimates of optimized OPs between several country pairs are more than five times greater than those of direct paths.