|
Hi
Those gaps are due to bit-swapping. The higher frequencies are affected more by noise, at some point perhaps for a tiny period of time they can't carry any data reliably, so they are turned off, those tones will not get re-enabled again until a resync. The data those tones were allocated to carry are moved elsewhere, and this results in your SNR lowering. Over time your SNR can erode enough that the modem drops the line and resync's, the tones come back into use until they are switch off again. This is all completely normal behaviour, and is why quite often ADSL lines drop and resync, it is what they are designed to do.
Looking at your graph and the shape of it, you have cross talk from a neighbouring pair/pairs.
Walking around with a radio isn't going to help, and you'll pick up noise from everywhere, just place it up against your router!
Regards
Phil
|
Pages in this thread: 
Print Thread
deleted
