Microsoft KB Archive/830614

= Systems Management Server 2003 bandwidth throttling does not completely use allocated bandwidth =

Article ID: 830614

Article Last Modified on 5/14/2007

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APPLIES TO


 * Microsoft Systems Management Server 2003

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SYMPTOMS
Microsoft Systems Management Server (SMS) 2003 bandwidth throttling for both the Remote Access Server (RAS) Sender and the Standard Sender may not use all the allocated bandwidth.



CAUSE
This problem occurs because the SMS 2003 RAS Sender and the SMS Standard Sender do not account for the time that it takes to transfer each data block (block transfer time). SMS bandwidth throttling is based on &quot;sleep time&quot;. Sleep time forces a delay between each sent data block.

For example, if the maximum available bandwidth is 40 Kbps and the Limit (% of connection bandwidth) setting for the RAS Sender or the Standard Sender is set to 75%, and the last sent block size was 120 KB, SMS uses the following formula to calculate the sleep time:

(KB) x (1 / ) x   (Kb/s) =   (seconds)

Note 1 KB = 8Kb

120 KB x (1 / .75) / 40 Kb/s = 32 seconds

This formula does not account for the block transfer time. You can use the following formula to calculate the block transfer time:

/  =

120 KB / 40 Kb/s = 24 seconds



Service pack information
To resolve this problem, install the latest service pack for Systems Management Server 2003.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

885643 How to obtain the latest Systems Management Server 2003 service pack

Hotfix information
A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Systems Management Server 2003 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites
You must have SMS 2003 Service Pack 2 (SP2) installed to apply this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

885643 How to obtain the latest Systems Management Server 2003 service pack

Restart requirement
You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.



WORKAROUND
You can use the formulas in the &quot;Cause&quot; section of this article to calculate the actual bandwidth for the SMS RAS Sender and the SMS Standard Sender. You must add the data block transfer time (24 seconds) and the sleep time (32 seconds) to calculate the overall time of 56 seconds and an actual bandwidth utilization factor of 43% and not 75% as specified in the Limit (% of connection bandwidth) setting of the SMS 2003 Sender properties.

You can use the following formula to calculate the actual bandwidth utilization factor:

(KB) /  (seconds) /   (Kb/s) =

120 KB/ 56s / 40 Kb/s =

42.8%

For example, when you set the Limit (% of connection bandwidth) setting to 25%, the total time is: 24 seconds for the data block transfer time, 96 seconds for the sleep time (for an overall time of 120 seconds), and an overall bandwidth utilization of 20%.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.

This problem was first corrected in Systems Management Server 2003 Service Pack 3.

Keywords: kbservicepack kbqfe kbfix kbhotfixserver kbbug KB830614

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