iOS 5 backups/syncs also over cellular data connection?

[Mdk1309]

This morning I woke up to a warning SMS of my carrier (Orange Austria), informing me that in my current accounting period I had generated costs of more then 300 Euros.

Checking online, I found that since the update to iOS 5 (on my iPhone 4), every night I have continuous transfer of 15 MB chunks of data, every 6 minutes. Although I'm having WLAN at home and Airplane Mode is turned on!

Syncing to iCloud and online Backup are turned on, but can the first generate these amounts of data? And the latter should only use the WLAN connection, shouldn't it?

For the remainder of this month, I have disabled all cellular data, but any suggestions on how to avoid this in the future? Any similiar experiences?


Personally I strongly suspect a bug in the backup routine, using 3G instead of WLAN (or backing up, even when no WLAN is currently available).


Any hints are gladly appreciated.

Best regards
Manuel

 

[apple95]

My wife encountered some similar behavior, which we haven't been able to determine the cause of it, but I am also suspecting backup over data. Have you been able to confirm this yet?

 

[Mdk1309]

Yes, I think I found the reason for the traffic, but it was an unexpected one: according to the itemised bill, the traffic was DOWNload, not UPload, as I first suspected.

By snooping the traffic I then found out that it originated from my Webdav calendars! There seems to be a subtle bug in iOS 5 in combination with my company's CMS, so suddenly the calendars are transferred in one neverending datastream, instead of just being updated according to schedule...

Before confirming that I also tried various combinations of enabled/disabled iCloud and Backup services, but to no avail.

Best regards
Manuel