# Updates: Windows refresh_pattern -i windowsupdate.com/.*\.(cab|exe|ms[i|u|f|p]|[ap]sf|wm[v|a]|dat|zip|psf) 43200 80% 129600 reload-into-ims refresh_pattern -i microsoft.com/.*\.(cab|exe|ms[i|u|f|p]|[ap]sf|wm[v|a]|dat|zip|psf) 43200 80% 129600 reload-into-ims refresh_pattern -i windows.com/.*\.(cab|exe|ms[i|u|f|p]|[ap]sf|wm[v|a]|dat|zip|psf) 43200 80% 129600 reload-into-ims refresh_pattern -i microsoft.com.akadns.net/.*\.(cab|exe|ms[i|u|f|p]|[ap]sf|wm[v|a]|dat|zip|psf) 43200 80% 129600 reload-into-ims refresh_pattern -i deploy.akamaitechnologies.com/.*\.(cab|exe|ms[i|u|f|p]|[ap]sf|wm[v|a]|dat|zip|psf) 43200 80% 129600 reload-into-ims
Sites like Microsoft’s windowsupdate.com, which virtually all Windows PCs update their OS from, are among the most bandwidth-intensive sites on some networks.
Unfortunately, they are not cacheable because they offer partial responses (http return code 206), which Squid presently does not cache.
Where you have control over the client machines, you can install Microsoft’s Update Server to handle caching for windowsupdate.
If you cannot use the Update Server, you can use Squid’s delay pools — a bandwidth management technique — to limit the portion of bandwidth that windowsupdate consumes during your peak periods.
The clients will then have to be online during off-peak periods to complete their updates.
Below, we configure one global delay pool at 64Kbps (8KBps).
Traffic for which the ACL of destination domain is windowsupdate.com during the peak period of 10:00-16:00 will be limited to 64Kbps.
acl winupdate dstdomain .windowsupdate.com acl peakperiod time 10:00-16:00 delay_pools 1 delay_class 1 1 # 64 Kbit/s delay_parameters 1 8000/8000 delay_access 1 allow winupdate peakperiod
After making changes like the ones above, Squid’s byte hit rate increased from about 8% to between 26-37%. If you are doing 33%, it means a third of all traffic is coming from your cache, and not from slower links across the Internet.