How do providers normally manage the 'up to' bit of the bandwidth?

[blackninja]

How do providers normally manage the 'up to' bit of the bandwidth?

I have just changed providers and previously my ADSL always connected at the same reported ADSL speed and it could be left on for literally weeks without issue ... however things are now different.

In my case now, I have a 4mb package that is on a 50:1 contention ratio and my ADSL router shows varying speeds when I connect .. sometimes it is 4400 and at others (like now it is 3100). Fair enough one might think ... but is this a normal situation?

Now, my issue is that if I connect at a non-busy time and get 4400 say then at busy times my line seems to go very hitchy and will usually drop out altogether at some point. When I reconnect I have the slower speed on my router and there are no issues other than having less than 4mb - this is a daily occurrance, understandably! I connect at a later (non-busy) time and get a faster ADSL connection ...

I thought that my connection to the exchange was fixed and would determine the maximum potential bandwidth (always capable of 4mb) and that load would determine what I actually get at a given point in time as throughput would vary. I want my router on (unattended) 24/7 but with this situation that is near impossible as it will hang at some point during the day and I have to reset.

 

[tolien]

It's not always capable of 4Mbps if it's connecting at 3100kbps and it has nothing to do with the ISP. It's all about your line and has nothing to do with whether it's a "busy time", the contention ratio or anything else.

 

[blackninja]

If its all about my line and nothing to do with the provider or busy periods then what is determining the variation in connection speed in a more or less reproducable manner (eg, generally higher in the morning then in the evening)?

 

[tolien]

The SNR margin nearly always fluctuates with time - interference from a whole load of things (heating, christmas lights, AM radio, power supplies, you name it) will mess with your ADSL service.

 

[blackninja]

OK - nothing to whinge to the ISP about then!

Ta

 

[Mattus]

Nope. Generally a line will be better in the daytime than in the evening - in the evening there tends to be more interference, which lowers the noise margin.