There is a new feature in WuInstall (WuInstall 1.2. PRO) which helps saving bandwidth.

Imagine the following scenario:
You have a downstream network in a remote location with 15 client machines and a local fileserver, which are updated using WSUS which is in the corporate headquarters, connected with a bandwidth-critical connection (or even updated via the Microsoft Update Site)

In the normal approach (unless you use a proxy), each update would habe to be downloaded 15 times (for each machine once).

It would be nice if only the first machine getting the update would download it to a cache, and the others would get it from there and put it into their local cache (Usually WINDOWSSoftwareDistributionDownload) - as simple as possible and unattended of course, using a command line script.

For example:
Let p:\TEMP be a shared directory, which all client machines can access with read-write permissions.

You can do like this:

c:\DATA\WuInstall>wuInstall /install_cache p:\temp /logfile c:\data\temp\inst.txt

For an the first client WuInstall puts the following:

2010/08/11-11:08:01  Checking cache for update: Windows Malicious Software Removal Tool - August 2010 (KB890830)
2010/08/11-11:08:01  Update Windows Malicious Software Removal Tool - August 2010 (KB890830) Multi-Lingual - Delta not found in cache directory p:temp20110b11-6dd2-4153-a76d-e660ec78ebed
2010/08/11-11:08:01  Update bundle not found, downloading...
2010/08/11-11:08:01  Copying downloads directly...
2010/08/11-11:08:01  Downloading: http://download.windowsupdate.com/msdownload/update/software/uprl/2010/08/windows-kb890830-v3.10-delta_b6366a428af17c9c7c524ebd15aafe3608d3fa39.
exe to p:temp20110b11-6dd2-4153-a76d-e660ec78ebed/windows-kb890830-v3.10-delta_b6366a428af17c9c7c524ebd15aafe3608d3fa39.
exe ... 
2010/08/11-11:08:13  OK
2010/08/11-11:08:14  Download OK
2010/08/11-11:08:14  Checking cache again...
2010/08/11-11:08:14  Update Windows Malicious Software Removal Tool - August 2010 (KB890830) Multi-Lingual - Delta found in cache directory, copying to local cache...
2010/08/11-11:08:15 OK

Now calling the same command for the second client (and all the others), WuInstall gets the update from the cache (P:TEMP) instead of downloading it:

2010/08/11-11:20:27  Checking cache for update: Windows Malicious Software Removal Tool - August 2010 (KB890830)
2010/08/11-11:20:28  Update Windows Malicious Software Removal Tool - August 2010 (KB890830) Multi-Lingual - Delta found in cache directory, copying to local cache...
2010/08/11-11:20:28 OK

You can also use /download_cache, just for downloading the updates to the local cache without installing them.

Do you want to see this feature in action? View a demonstration of the WuInstall install_cache feature.