http://blogs.msdn.com/hgao/archive/2...10/428194.aspx

Avalanche is expected of the following

1. Avalanche is more resilient to peer leaving the network: Avalanche combines chunks (like a XOR) before sending them, you don’t need to have a specific chunk A, you only need enough combination that you can extract chunk A out

2. Avalanche imposes less load on the servers: BitTorrent servers needs to track which clients have chunk A, but Avalanche doesn’t.

3. Avalanche added feature for security reasons. It restricts to only distribute MS signed package

4. Avalanche could provide about 2-3 times faster downloads than BitTorrent and about half the server requirements (Based on http://www.pam2004.org/papers/148.pdf, BitTorrent was used to distribute the Linux RedHat 9 ISO (1.77 GB) to more than 180,000 clients (over 5 months) using two servers with not super high end links (I have heard 5Mbps, needs to be confirmed).
http://research.microsoft.com/~pablo/avalanche.htm

Avalanche provides a cost effective, internet scalable and very fast file distribution solution (e.g. for TV on-demand, patches, software distribution). By leveraging desktop PCs, Avalanche aids in the distribution process, relieving congested servers and network links from most of the traffic.

Existing P2P file delivery systems use swarming techniques to simultaneously obtain different pieces of a file from multiple nodes. One problem of such systems is that as the number of receivers increases it becomes harder to do optimal scheduling of pieces to nodes. One possible solution is to use a heuristic that prioritizes exchanges of "locally rarest" pieces. But such local-rarest policies often fail to identify the "globally rarest" piece since peers have a limited view of the network. The end result is slower downloads, stalled transfers, etc.

Avalanche fixes these problems using network coding. Instead of distributing the blocks of the file, peers produce linear combinations of the blocks they already hold. Such combinations are distributed together with a tag that describes the parameters in the combination. Any peer can generate new unique combinations from the combinations it already has. When a peer has enough independent combinations, it can decode and build the original file.

Seems even MS is jumping on the bandwagon...wonder what took them so long.

A_T