Editing Squid (software) (section)

==Media-range limits==
For example, a feature of the HTTP protocol is to limit a request to the range of data in the resource being referenced. This feature is used extensively by video streaming websites such as [[YouTube]], so that if a user clicks to the middle of the video progress bar, the server can begin to send data from the middle of the file, rather than sending the entire file from the beginning and the user waiting for the preceding data to finish loading.

Partial downloads are also extensively used by Microsoft [[Windows Update]] so that extremely large update packages can download in the background and pause halfway through the download, if the user turns off their computer or disconnects from the Internet.

The [[Metalink]] download format enables clients to do segmented downloads by issuing partial requests and spreading these over a number of mirrors.

Squid can relay partial requests to the origin web server. In order for a partial request to be satisfied at a fast speed from cache, Squid requires a full copy of the same object to already exist in its storage.

If a proxy video user is watching a video stream and browses to a different page before the video completely downloads, Squid cannot keep the partial download for reuse and simply discards the data. Special configuration is required to force such downloads to continue and be cached.<ref>{{cite web |title=Squid Configuration Reference |url=http://www.squid-cache.org/Doc/config/quick_abort_min/ |access-date=26 November 2012}}</ref>