Darwin Streaming Server: Open, Functional and Free

Through an internal access module, it is possible to control client access to streaming content on the DSS. Access can be controlled per individual or by group. All access to the Streaming Server is handled by this module, including Playlist access and access to the Admin Server itself. It is important to note, though, that this is access control only, as DSS offers neither encryption of content nor other Digital Rights Management (DRM) capabilities.

For access to streaming content, there are two types of authentication available: Basic and Digest. Digest is most secure and is used by default. However, to use Digest authentication, clients must be running QuickTime 5. Clients using previous versions will be denied access and receive an 'unauthorized' error message. Clients using QuickTime 4.1 or greater can access content using Basic authentication, but earlier clients will receive the 'unauthorized' error message when attempting to access media using even Basic authentication. Changing the authentication method is done by changing a setting in the Admin Server.

The process for setting up authentication is pretty straight forward and explained well in the user manual PDF file bundled with the application. One nice feature, is that under your movies directory, you can create other directories to contain movies. Then each of these directories can contain their own access file naming users or groups that can access the files in that directory. I created several directories and users, and this all worked perfectly.

Skip Protection

What is Skip Protection? This is a grey area for me at the moment. Nobody seems to be able to give a straight answer about what exactly this Skip Protection is. One aspect of it is aggressive buffering, wherein the client will buffer while rendering a stream if bandwidth allows both the playing of the stream and buffering on top of that. Ostensibly, at it’s maximum Skip Protection will keep a stream playing for about 15 seconds after loss of connection. My testing fell short of that, but my limited tests may not have met the criteria for a full complement of Skip Protection buffering to take place. Note that these criteria are currently undocumented, unless one counts the source code as a user's guide, which I chose not to do.

Performance

I tested the Streaming Server on a number of machines, including a 533MHz G4 running OS X, an 800MHz Pentium II (Linux), and a 120MHz Pentium (Linux) with only 48MB of RAM — performance was good in all cases. The Admin Server Perl application was a little slow on the 120MHz machine. However, this slowness did not manifest when streaming large QuickTime files to clients on other machines from the little 120MHz system. The real performance evaluation comes in load testing the theoretical 3,000 connection limit, with various types and sizes of streams, but that testing will have to wait for another review.

The Bottom Line

Overall, the Darwin Streaming Server worked well, and although it is not quite a polished package, the DSS is a powerful, and free, tool. Until this product gains the 'fit and finish' of off-the-shelf software, the open source aspect will allow users to work around any quirks found, in any manner they wish. The only tinkering I needed to do was at the Perl script level; the actual server code was quite mature.

While working on this review, I asked questions and reported bugs to the Darwin developers on numerous occasions. They were helpful and, true to the nature of the open source community, they listened to complaints and suggestions; they may very well modify the code for you if you make a valid point.

The Darwin releases do come slowly, though, and you may wish to get the latest and greatest from CVS and compile it yourself to get the latest fixes. Information on access to CVS can be found at the Apple Public Source Web site at www.publicsource.apple.com. In the mean time, you may still have to get your hands a little dirty.

From a computer giant like Apple, even an open source product would be expected to come polished and complete. But then again, coming from a computer giant, would we expect an open source product at all? The bottom line is that it’s here, and it works. If you want to keep your hands clean, use the DSS on OS X. Either way, Apple’s slogan, 'No Server Tax,' speaks for itself. With Free BSD or Linux, and DSS, you now have a free and royalty-free option for streaming content to a massive number of already installed QuickTime players. And that’s not hype: It’s real, and it’s here right now.