>> I was an ISP in the 1990s and our first DSL offerings were SDSL
>> symmetric services to replace more expensive T-1 circuits. When
>> we got into residential it was with SDSL and then the consumers
>> wanted more downstream so ADSL was invented. I was there, I
>> know this.
>So was I and my experience was different. We decided that it would be more
>profitable as a small ISP to re-sell Bell Canada's ADSL than to try to
>unbundle central offices all over the place. The arguments from the business
>side had >nothing whatsoever to do with symmetry or lack thereof. The choice
>of technology was entirely by the ILEC.
What I am trying to tell you is that Bell Canada was way behind the curve in
deployment to DSL technology. I am coming to you from the perspective of a guy
who designed and built DSL networks not a reseller. By the time the LEC
started selling you ADSL, the market had already spoken and ADSL was the
customer's choice. The LECs looked at what us facilities based ISPs deployed
and decided to start reselling the same thing. If they had the demand to
resell SDSL, they would have (and they do, it is called a clear channel DS-1
port). It just makes no difference to them, a loop and a port is just a loop
and a port.
>> To that I will just say that if your average user spend as much
>> time videoconferencing as they do watching streaming media then
>> they are probably a business.
>No, you misunderstand. I don't dispute that the area under end-user traffic
>statistics graphs is asymmetric. But that the maximum value -- particularly
>the instantaneous maximum value which you don't see with five minute sampling
>-- >wants to be quite a lot higher than it can be with a very asymmetric
>circuit. If someone works from home one day a week and has a videoconference
>or too, we still want that to work well, right?
The bottom line is that you have to tell me how much downstream speed you want
to give up to get more upstream speed. If you don't want that then you are
just telling me you want more overall speed which is a different argument.
Videoconferencing is a red herring argument because it is also asymmetric in
most cases and the bandwidth of a videoconference does not even come close to
that of a movie download where quality matters more than lag.
>And perfect symmetry is not necessary. Would I notice the difference between
>60/60 and 60/40 or even 60/20? Probably not really as long as both numbers are
>significantly more than the expected peak rate. But 24/1.5, a factor of 16,
>>is a very different story.
If you don't like the up to down ratio, I get it. The problem is you either
need more intelligent networks to automatically set this ratio based on usage
(which is not actually easy, remember RSVP anyone?) or you have to try to
please most of the people most of the time which is how it works today.
Steven Naslund
Chicago IL
