Understanding HTTP for streaming

Why you should enable HTTP

Although HTTP is not normally associated with streaming media, HTTP can be used as a streaming transport when other ports are blocked. If a client cannot connect to the streaming server using UDP or TCP, the client will try to connect using HTTP.

NetCache handles HTTP streaming traffic in the following ways:

Client-side HTTP encapsulation
Server-side HTTP encapsulation
HTTP proxying

When NetCache uses client-side HTTP encapsulation

HTTP encapsulation is the process by which a streaming media protocol is tunneled over HTTP requests.

When a client attempts to contact the streaming server using HTTP, NetCache intercepts the request and attempts to fetch the content from the streaming server using TCP or HTTP (if the content is not cached). If NetCache can retrieve the content using TCP, NetCache then encapsulates the streaming data into HTTP for delivery to the client.

NetCache performs client-side HTTP encapsulation for Windows Media, RealNetworks, and QuickTime clients.

When NetCache uses server-side HTTP encapsulation

If NetCache is behind a firewall that blocks TCP or UDP traffic, or if the streaming server is only listening on an HTTP port, NetCache retrieves streaming content using HTTP encapsulation. When NetCache uses server-side HTTP encapsulation to retrieve streaming content, NetCache caches or splits the content and attempts to send it to clients using UDP, TCP, or HTTP (in that order).

NetCache performs server-side HTTP encapsulation for Windows Media, RealNetworks, and QuickTime clients.

HTTP proxying

If you have not installed a streaming license or if streaming is disabled, NetCache will proxy streaming traffic over HTTP. NetCache does not cache or split HTTP-proxied streaming traffic.

Clients using HTTP encapsulation are controlled by the same user access and caching behavior rules as all other streaming requests. See User access and cacheability rules for HTTP-encapsulated streaming media for more information.