Numpty ADSL question
Discussion
I was going to say it's simply because home users generally want to download a lot more data then they want to upload. So it makes a lot of sense to bias the available bandwidth in this way. Was just double checking something on Wikipedia though, and it included this. So my simple version above is basically right, but there's some technical reasons behind it as well.
I promote your question from "numpty" to "interesting", as I learnt something!
I promote your question from "numpty" to "interesting", as I learnt something!
wikipedia said:
The distinguishing characteristic of ADSL over other forms of DSL is that the bandwidth is greater in the direction to the customer premises than the reverse, giving rise to is asymmetric characteristic. Providers usually market ADSL as a service for consumers to connect to the Internet in a relatively passive mode: able to use the higher speed direction for the download from the Internet but not needing to run servers that would require high speed in the other direction.
There are both technical and marketing reasons why ADSL is in many places the most common type offered to home users. On the technical side, there is likely to be more crosstalk from other circuits at the Digital Subscriber Line Access Multiplexer (DSLAM) end (where the wires from many local loops are close to each other) than at the customer premises. Thus the upload signal is weakest at the noisiest part of the local loop, while the download signal is strongest at the noisiest part of the local loop. It therefore makes technical sense to have the DSLAM transmit at a higher bit rate than does the modem on the customer end. Since the typical home user in fact does prefer a higher download speed, the telephone companies chose to make a virtue out of necessity, hence ADSL. On the marketing side, limiting upload speeds limits the attractiveness of this service to business customers, often causing them to purchase higher cost Leased line services instead. In this fashion, it segments the digital communications market between business and home users.
There are both technical and marketing reasons why ADSL is in many places the most common type offered to home users. On the technical side, there is likely to be more crosstalk from other circuits at the Digital Subscriber Line Access Multiplexer (DSLAM) end (where the wires from many local loops are close to each other) than at the customer premises. Thus the upload signal is weakest at the noisiest part of the local loop, while the download signal is strongest at the noisiest part of the local loop. It therefore makes technical sense to have the DSLAM transmit at a higher bit rate than does the modem on the customer end. Since the typical home user in fact does prefer a higher download speed, the telephone companies chose to make a virtue out of necessity, hence ADSL. On the marketing side, limiting upload speeds limits the attractiveness of this service to business customers, often causing them to purchase higher cost Leased line services instead. In this fashion, it segments the digital communications market between business and home users.
As I understand it, it's like the following:
Think of a 10 lane motorway between Manchester and Liverpool.
1 lane going from Manchester to Liverpool - quite slow traffic
9 lanes going from Liverpool to Manchester - a lot of traffic getting to Manchester quickly
So to improve speeds from Manchester to Liverpool, you need to change the ratio, say 5 each.
However this means that Manchester to Liverpool traffic is a lot slower. The thing is, up until recently most people have been travelling from Liverpool to Manchester with few needing to do the opposite journey (i.e. a lot of people download a lot but their upload requirements are a low lower).
Anyway, as more and more upload (e.g. online backups etc.) rather than download data, I suspect the ratio will close (esp as general speed/capacity is a lot higher nowadays, e.g. 4 lanes to Liverpool and 16 to Manchester)
My analogy could all be bordocks of course
In fact, I think it's probably nothing like what really happens
OH and children from Liverpool with an inferiority complex and a chip on their shoulder about how many people acutally drive there from Manchester, F right Off!
I just picked two random cities for examples sake
Think of a 10 lane motorway between Manchester and Liverpool.
1 lane going from Manchester to Liverpool - quite slow traffic
9 lanes going from Liverpool to Manchester - a lot of traffic getting to Manchester quickly
So to improve speeds from Manchester to Liverpool, you need to change the ratio, say 5 each.
However this means that Manchester to Liverpool traffic is a lot slower. The thing is, up until recently most people have been travelling from Liverpool to Manchester with few needing to do the opposite journey (i.e. a lot of people download a lot but their upload requirements are a low lower).
Anyway, as more and more upload (e.g. online backups etc.) rather than download data, I suspect the ratio will close (esp as general speed/capacity is a lot higher nowadays, e.g. 4 lanes to Liverpool and 16 to Manchester)
My analogy could all be bordocks of course
In fact, I think it's probably nothing like what really happens OH and children from Liverpool with an inferiority complex and a chip on their shoulder about how many people acutally drive there from Manchester, F right Off!
I just picked two random cities for examples sake Edited by Dracoro on Wednesday 17th March 18:39
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