Package Servers show a very high number of packages with a pending download status. The number of pending packages may decrease by a few per day but not fast enough to service the demands of client computers needing to download them in their respective sites.
In the local agent log files there are many of the following warning and error sequences (excerpts):
Description: Unable to map network drive for account 'DOMAIN\ralt01' to '\\NSServer\NSSWD_cc3d114d-0c93-49de-a982-bcc6e8b9db6e$': No network provider accepted the given network path (-2147023693)
Description: GetFiles '\\NSServer\NSSWD_cc3d114d-0c93-49de-a982-bcc6e8b9db6e$\WindowsXP-KB969898-x86-ENU.exe'->'E:\Program Files\Altiris\Altiris Agent\Package Delivery\cc3d114d-0c93-49de-a982-bcc6e8b9db6e\cache\WindowsXP-KB969898-x86-ENU.exe' failed: UncTransfer: Failed to open source file: The network path was not found (-2147024843)
Description: Download Package failed: UncTransfer: Failed to open source file: The network path was not found. (-2147024843)
Description: Error while downloading package: UncTransfer: Failed to open source file: The network path was not found. (-2147024843)
Description: Error while downloading package: Server is busy. Package sources request is backing off (-2147467259)
An attempt to manually open a UNC path to the source also fails e.g. \\NSServer\
The problem is obviously that there is a network problem preventing the PS from downloading packages via UNC path which will need to be identified by a network administrator.
The problem may also be compounded by the fact that the NS is prevented from generating and publishing code bases for download via HTTP. This is set in CoreSettings.config. As a result the PS and outlying clients are forced to attempt downloading packages exclusively via UNC paths, which may not always be available.
Unless rules are in place which prohibit the publishing and downloading of packages via HTTP you may wish to review and implement the following linked KB articles which explain how to verify if the NS is set for this option and how to configure it to publish code bases for both UNC and/or HTTP. By providing two download methods the process runs much faster. If one method is not responding they can be obtained by the secondary method.