Re: [squid-users] Windows ASF streaming format

From: Joe Cooper <>
Date: Tue, 12 Feb 2002 00:14:29 -0600

There's more than one way to skin a cat, khiz.

I was not referring to CONNECT tunnels. Streaming servers, when talking
to stream clients via HTTP build data-filled HTTP replies specifically
for the client--intercepting and storing that stream to be played on
another client, or even on the same client at a later time, simply
wouldn't work in most, if not all cases. Anyway, I use the term
'tunnel' generically, not in the sense of an SSL tunnel.

Regardless of whether the data is labelled cacheable, the data generally
can't be used by any other client. It /is/ marked uncacheable, but even
if you forced it to be cached it wouldn't play back on any client at any
later time. This is a fundamental part of the copy protection schemes
used by these protocols and formats. There may be some such streaming
objects which are not copy protected, but not enough to make it worth
the trouble to try to enforce caching of all such objects--and in some,
if not all cases, the cache couldn't correctly serve even the
non-protected objects to clients because of the rather odd way in which
streams over HTTP work.

This isn't a simple data storage issue. These systems are designed to
prevent simple copying or storing of the content. Copy protection is
alive and well in the streaming media world... The only solution to this
problem is the break the copy protection and reverse engineer the
protocol so that you can then talk to the client in it's native
language. This is illegal in the US and some other countries.

Sorry...Nice thought, but not gonna happen anytime soon in Open Source
software, unfortunately.

khiz code wrote:

> Hi joe
> when u say tunnelled do you mean to say the CONNECT directive used like for
> i dont think that streaming is done that way .
> i ve used ethreal and it doesnt show me any such thing
> then will the data be cacheable
> Khiz
> --- Joe Cooper <> wrote:
>>Most likely not. Most streaming formats include in the protocol (even
>>when tunneled over HTTP) copy-protection mechanisms which prevent them
>>from being played multiple times. I'm sure WSM has these same features.
>>In the case of Real, and maybe WSM as well, there is a special purpose
>>proxy that provides splitting and caching of the data. The license for
>>this software is usually outlandishly expensive (RealProxy costs $2,000
>>for it's lowest cost user license).
>>khiz code wrote:
>>>Hi all
>>> i just wanted to know that if windows streaming media is delivered via
>>>then can it be cached by squid, the asf files that is
>>>Also for real time media files that are delivered via HTTP
>>Joe Cooper <>
>>Web Caching Appliances and Support
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Joe Cooper <>
Web Caching Appliances and Support
Received on Mon Feb 11 2002 - 23:14:42 MST

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