New to this whole ADSL thing, so forgive me if this is something obvious. We've got a Vodafone Station that will give me generally around 350-400+ KB/s download and 80ish KB/s upload most of the time. However, after 24-36 hours, the speed will drop down to something closer to 300ish KB/s download and 20-30(!) KB/s upload. When I reboot the router, it goes completely back to normal.
Took these two speedtests not long ago which shows the behaviour:
Before reboot: https://www.speedtest.net/my-result/3539767247
After reboot: https://www.speedtest.net/my-result/3539771034
The vodafone station's config page also shows the changes under it's connection details (from 0.26Mb/s or so to 1.02Mb/s upload).