Topic last updated—November 2007
In Microsoft System Center Configuration Manager 2007, by default, branch distribution points normally receive packages in the same way that standard distribution points do. When an administrator selects the distribution points to which a package will be copied, branch distribution points can also be selected at that point. When this is done, branch distribution points selected will download the package just as a standard distribution point would.
However, the administrator can specify that the package should not be downloaded from the standard distribution point to the branch distribution point until it is requested by a client computer. This preserves bandwidth in the following ways:
- The package is not transferred to the branch
office until at least one client requests the package.
- When the package is transferred to the branch
distribution point, it uses Background Intelligent Transfer Service
(BITS) instead of server message blocks (SMBs).
This option is called on-demand package distribution. This functionality is set on a package-by-package basis, using either the New Package Wizard (when a package is first created) or the Package <Name> Properties dialog box (for existing packages).
|On-demand package distribution is available only for protected branch distribution points and only from clients within the protected boundaries. If a client is not within those protected boundaries or the branch distribution point is not protected, on-demand distribution will fail.|
If a package has been set to allow on-demand package distribution, the client that wants to receive the advertised program sends a standard request for the program to its branch distribution point. If the branch distribution point has downloaded the program already, it will be provided to the client. (This might be because the program was originally copied to the branch distribution point or because it previously went through the on-demand process, which stores a copy of the package on the branch distribution point.)
When the client asks the management point for content location, if the package is configured for on-demand package distribution and is copied to a branch distribution point, the management point includes the branch distribution point on the list but indicates that the content is pending. The pending designation creates an advertisement to send the package to the branch distribution point, but like any advertisement, the branch distribution point does not receive the advertisement until the next policy polling interval. After the branch distribution point receives the advertisement, it sends its own content location request and then downloads the content.
On-demand package distribution is transparent to the client; however, the client might experience a delay in receiving the package depending on the following factors:
- The size of the package
- The available bandwidth to the branch
- How frequently the branch distribution point
client component checks for policy
- BITS throttling settings
On-demand package distribution is a good choice if you have packages that might be needed by only a few clients at the branch office. However, if you have packages that require urgent distribution, such as critical software updates, consider the possible package delay before marking the package for on-demand package distribution.
Another way to preserve bandwidth to the branch office is to prestage the content on the distribution point by using an out-of-band process. For more information, see How to Prestage Packages on a Branch Distribution Point.
If you use a long polling interval for client policy retrieval, you can enable a collection-specific policy polling interval on a collection and add your branch distribution points to that collection. For more information, see Collection Name Settings: Advanced Tab.
|Packages created using the Distribute Software Wizard cannot have on-demand distribution set when the package is created. For these packages, it must be set by using the Package <Name> Properties dialog box.|