I have had a problem recently with an 878 using SDSL.
I recently lost connection to the device after a thunderstorm and assumed either a tail problem or a blown modem.
After several tests by BT the line passed as clear and after changing the 878, there was still no connection.
Reviewing my RANCID configs for the past 6 months shows that the config on the Controller DSL 0 changed over time. I originally set the line rate to auto, which was lated changed to hard code 2304k. This I have no problem with....unfortunately thats not the end of it.
The latest config (which was applied to the new router) shows the line rate at 1152k. When I double checked that yesterday, it had changed to 576k. Now, there has been no outside intervention, only I have access. The logs show nothing to prove that anything changed.
I have fixed the issue by resetting the line rate to auto, but what I need to know or understand is how has this changed without my intervention. This is not a negotiated rate as far as I was aware.
I would appreciate any help. Thanks