Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Asynchronous Layered Coding is an Internet protocol of the IETF specified in RFC 3450 and described as a massively scalable reliable content delivery protocol. It was adopted as an experimental protocol in December 2002 and still is as of January 2006. Asynchronous Layered Coding (ALC) is a massively scalable reliable content delivery protocol, for multiple rate congestion controlled reliable content delivery. The protocol is specifically designed to provide massive scalability using IP multicast as the underlying network service. Massive scalability in this context means the number of concurrent receivers for an object is potentially in the millions, the aggregate size of objects to be delivered in a session ranges from hundreds of kilobytes to hundreds of gigabytes, each receiver can initiate reception of an object asynchronously, the reception rate of each receiver in the session is the maximum fair bandwidth available between that receiver and the sender, and all of this can be supported using a single sender.