Client-side method for identifying an optimal server

Abstract

A client player performs a query to a nameserver against a network map of Internet traffic conditions. The query is made asking for a particular service (e.g., RTSP) via a particular protocol (TCP) in a particular domain. In response, the nameserver returns a set of one or more tokens, with each token defining a machine or, in the preferred embodiment, a group of machines, from which the player should seek to obtain the stream. The player may then optionally perform one or more tests to determine which of a set of servers provides a best quality of service for the stream. That server is then used to retrieve the stream. Periodically, the client player code repeats the query during stream playback to determine whether there is a better source for the stream. If a better source exists, the player performs a switch to the better stream source “on the fly” if appropriate to maintain and / or enhance the quality of service. Preferably, the client player publishes data identifying why it selected a particular server, and such data may be used to augment the network map used for subsequent request routing determinations.

Description

RELATED APPLICATION[0001]This application is based on and claims priority from provisional application Ser. No. 60 / 205,636, filed May 18, 2000, and assigned to the assignee of this application.BACKGROUND OF THE INVENTION[0002]1. Technical Field[0003]The present invention relates generally to high-performance, fault-tolerant content delivery in a content delivery network (CDN).[0004]2. Description of the Related Art[0005]Streaming media is a type of Internet content that has the important characteristic of being able to be played while still in the process of being downloaded. A client can play the first packet of the stream, and decompress the second, while receiving the third. Thus, an end user can start enjoying the multimedia without waiting to the end of transmission. Streaming is very useful for delivering media because media files tend to be large particularly as the duration of the programming increases. Indeed, for live events, the file size is, in effect, infinite. To view ...

AI Technical Summary

Benefits of technology

The patent describes a system that allows a client machine to query a server to find the best source for content delivery. The server provides a set of options for the client to choose from, and the client tests each option to find the highest quality of service. The server then retrieves the content based on the client's choice. The client can also repeat the query during playback to find a better source for the stream. The client publishes data back to the server to help improve the network map used for routing future requests. The technical effect of this system is to improve the quality of service for content delivery by providing multiple options for the client to choose from and testing each option to find the highest quality of service.

Problems solved by technology

In general, streaming audio can be FM quality, but, given typical bandwidth constraints, streaming video is poor by TV standards, with smaller screens, lower resolution, and fewer frames per second.

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