> Re: [LINK] The PLAN, and broadband speeds?

[steve jenkin]

Karl Auer wrote on 22/6/07 3:43 PM:

I'll back Karl against Tony ("1.5Mbps is all I need")

In 1984 an experienced engineer at O.T.C. stated a well thought out
view. It was correct in engineering terms:
    "e-mail only ever needs 300bps (30 char/sec).  You can't read that
fast (360 words/minute)"

Correct in the context of the time.  Times & technologies have changed.

So, does Tony need 300bps or the 5,000-fold higher speed he now enjoys
to read his email??
[Compare the original 1981 4.77Mhz 8086 IBM PC. After 20 years,  CPU's
were around 1-2,000 faster.]

The one constant in our field is Change.
Also, it's impossible to accurately predict very far ahead.
And we're always resource constrained.  "need more disk, more RAM, more
MHz, ..."

=> We can be certain that we don't know what digital services/life will
be like in 20 years.
=> History informs us that novel applications will be widely taken up
and tax the limits of systems, quickly.
=> And digital capacity demand to increase 1-10,000 times [1-10Gbps/house]

Related comment - what's the cost difference between FO transceivers for
100Mbps and 1,000Mbps ethernet??
Same fibre for 100M, 1G and 10G.  10Gbps transceivers are a lot more
expensive.
Older technologies basically cost the same [and sometimes oldest is more
expensive]

The options for household fibre should be 100M or 1G.
Additional dark fibre for redundancy/breakage or multiple
carriers/systems. [e.g Neighbourhood LAN]
After that, use a WDM (Wave Division Multiplexing) system. Or even for
multiple carriers.

The real cost is the upstream link. What level of "over-subscription"
will the Telco provide - at what cost.
[If a 100M switch has 48 ports, aggregate capacity/demand is 4800M.  If
there is a single 1G up-link, then the ports are 4.8 times
over-subscribed].  100:1 over-subscription is not uncommon. 1:1 is used
in the best server rooms.]

s
> On Fri, 2007-06-22 at 12:24 +1000, Stewart Fist wrote:
>   
>> It makes no sense to design for the extreme user
>>     
>
> Yes, it does. Because today's extreme user is tomorrow's run-of-the mill
> average user.
>
>   
>> Anyhow, we know that terminal equipment will get cheaper and better at a
>> rate faster than human requirements will change, so anything around
>> 30-50Mb/s is an acceptable standard for now.
>>     
>
> "For now" indeed. So aim for *at least* double that. Quadruple would be
> more sensible, though still overly conservative.
>
> Regards, K.
>
>   


-- 
Steve Jenkin, Info Tech, Systems and Design Specialist.
0412 786 915 (+61 412 786 915)
PO Box 48, Kippax ACT 2615, AUSTRALIA

sjenkin at canb.auug.org.au http://www.canb.auug.org.au/~sjenkin