Introducing Media Player (MMS) protocol in LoadRunner!

Posted: April 21st, 2008 | Author: TnT Admin | Filed under: Concepts | Tags: , | No Comments »

Media Player (MMS) protocol allows the load testing of video streaming application, in particularly for this protocol, Windows Media Server.

Before we start off, I want to put forward that this is Media Player (MMS) protocol from the Web 2.0 Bundle license, and not MMS (Multimedia Messaging Service) which is from the Wireless Bundle license. This is a little bit confusing in the names they used (for me) but I guessed we have to make do with it. When you are looking for function help, you can differ both protocols with their prefixes; take note that Media Player (MMS) uses mms_ prefixes for its APIs while MMS (Multimedia Messaging Services) uses mm_ prefixes.

Media Player (MMS) protocol actually works only on replay. That’s to say, you won’t be able to record anything from the browser or the Media Player Client. What you need to do is to code the entire script to access the MMS videos at its URL (e.g. you will have to provide the full URL mms://aries/happy.wmv in the mms_play function). The supported video types are those utilizing the MMS protocol to stream.

As you will be providing the URL directly, the script is actually sending request to the Windows Media Server publishing point for it to send in the streams without going though any application. Therefore, if you need to go through some activities on a web page or application before reaching the video URL, in the replay, all the activities will not be executed EXCEPT accessing the video URL. Example:

    1. User access application (http://aries/default.aspx)
    2. Login Page loads and user logins (http://aries/default.aspx)
    3. Home Page loads and user access Video Page (http://aries/home.aspx)
    4. Video Page loads and user access happy.wmv from the list of videos (http://aries/video.aspx)
    5. Window Media Player launches and starts playing on the client machine (mms://aries/happy.wmv)

Note:
For [5], it may deviate depending on how the application is designed to play streaming videos. It can be in the conventional Windows Media Player or it can be in the form of browser plugin.

When you are scripting, you are actually touching on [5] where the script plays the video URL directly. So, the steps from [1] to [4] is executed in the script.

Before you perform any replay, you will also need to ensure that WMLoad.asf is included in the ASFroot directory (or the directory that you stored the videos) or %systemdrive%/WMpub/WMroot. I know it’s a little vague here but I will fill that in a subsequent article. Instructions for creating WMLoad.asf can be found in HP Software Support, Error: “-17999: MMS Check : Host access denied, mms:///wmload.asf not available or missing” The basic concept of this file is, it acts like a security feature to prevent “unauthorized” personnel to load the Window Media Server with requests. You can refer to Checking Server Performance with Windows Media Load Simulator for more information with WMLoad.asf.

If you are working in a closed environments or Intranet where there is a high level of security control on the ports, you will need to have all streaming ports opened from the Load Generators (LG) to the Windows Media Server publishing point (treat the LG like a normal user location). The incoming TCP 80, 554, and 1755, UDP 1755 and 5005, while for outgoing UDP 1024 through 5000 and 5004 needs to be opened. More information on the ports can be consulted with Microsoft, “How to configure firewalls and Network Address Translation (NAT) for Windows Media Services 9 Series”.

In summary,

  • Do not get confused with Media Player (MMS) with Multimedia Messaging Service (MMS).
  • Media Player (MMS) only works on playback. No recording feature for this protocol.
  • Media Player (MMS) replays directly on the Window Media Server.
  • WMLoad.asf needs to exist on the Windows Media Server in order for load testing to work.
  • Treat the LG like a normal user accessing the Windows Media Server with the necessary ports opened.

Related Posts

Leave a Reply