In ExOS v7.4.1 or later, it it seen that iOS / Apple Updates are not being cached properly in environments with Edge Cache.
System updates to Apple Devices (via iTunes, or through actual 'Apple Updates') are important to classify and cache correctly. In firmware version v7.4.1 through v7.4.3, it is possible to find that even with edge cache enabled and caching all traffic, Apple and iOS updates are excluded from this, providing no reduction on WAN traffic, regardless of how many devices are updating. This can be seen when 'Apple Updates' are not striped in blue in the Real Time Monitor, or if there is not a significant difference in the Edge Cache Reduction (Monitor > Optimization, "Edge Cache" tab graph) when it is known that many devices should be using Apple Updates.
In v7.4.1, the way that edge cache interacted with application classifications was changed slightly, and it created a bug, where even though Apple Updates would come in and should be cached, they were not being sent to the edge cache engine.
ExOS 7.4.4u2 fixes this problem. Please see the release notes
for more information.