nemesis wrote:

> the problem is that packet loss is not as cheap as with networked data...

That is, indeed, a small problem. (!)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

Post a reply to this message

>> ADSL2+ is available pretty much everywhere here in Germany.  If I paid 10 
>> euro more per month I could have 16 Mbit/s instead of 8.  Also if I lived 
>> about 5 km closer to Munich I could get VDSL2 which is 50 Mbit/s :-D

Dream on. What you get depends on where you live. If you live in a city, 
perferably in the heart of a large city, then you are right. If you happen 
to live in the outskirts, no chance.

Examples from Berlin (German capital) and surrounding areas:

- Berlin outskirts, near the former Berlin wall (1 Mbit/s downstream, 128 kB 
upstream)
- regular street but: street surface is sand - when it rains the area 
becomes unpassable, have seen more sound streets in Egypt - at least they 
were dry...

- Brieselang, 11.000 inhabitants, 15km west of Berlin
- center of town, 1 minute away from train station (3 Mbit/s downstream)
- other, more remote areas: less than 1Mbit/s

- other areas in east Germany (the areas where there are just 20 year old 
glass-fibre cables available)
- ISDN available only, no ADSL (max. 2x 64 kbit/s at forbidding cost)

Post a reply to this message

> What you get depends on where you live. If you live in a city, perferably 
> in the heart of a large city, then you are right. If you happen to live in 
> the outskirts, no chance.

I guess Munich just has good support in the outskirts too.  Now I live 30 km 
from the centre and get 6 Mbit/s (not sure if this is the limit of my line, 
my plan/modem is max 6 mbit/s).  According to this map of where VDSL is 
available:

http://entertain.eki.t-home.de/hilfe-und-service/verfuegbarkeit-vdsl-ausbaustatus/

most of the towns/suburbs around me have VDSL but I don't :-(  It looks to 
me like pretty much the entire population of Munich itself is covered by 
VDSL, and a lot of the towns/villages surrounding it.

But like you say, I guess you need to live in or near a large city to get it 
currently.

Post a reply to this message

> I guess Munich just has good support in the outskirts too.  Now I live 30 
> km from the centre and get 6 Mbit/s (not sure if this is the limit of my 
> line, my plan/modem is max 6 mbit/s).  According to this map of where VDSL 
> is available:

Out of idle curiosity: have you actually measured data-transfer?

I pay for 6Mbit/s but get only 3Mbit/s. Of course, all kinds of people want 
to sell me flat rates with "up to 16 Mbit/s" - but when I ask them to give 
me a written statement that I >will < be able to use at least  a 6 Mbit/s 
line, I never ever hear of them again.

God, how I hate advertisements with "up to" or "starting from"...

It's a bit like trying to sell a 40 year old VW beetle and advertising that 
it will be able to travel at speeds >up to< 800.000 km/h...

Incindentally it actually does travel this fast provided you look at it from 
the center of our galaxy. ;-) The actual speed and direction of it relative 
to your own street can be seen as a mere pertubation in this case. 
Everything just depends on your standpoint...

(For the more conventionally minded resellers of used cars: we can safely 
assume that any car can travel at speeds of up to 200 km/h, albeit briefly. 
Just push it off the cliff of your choice.)

Post a reply to this message

TC wrote:

> Out of idle curiosity: have you actually measured data-transfer?
> 
> I pay for 6Mbit/s but get only 3Mbit/s. Of course, all kinds of people want 
> to sell me flat rates with "up to 16 Mbit/s" - but when I ask them to give 
> me a written statement that I >will < be able to use at least  a 6 Mbit/s 
> line, I never ever hear of them again.
> 
> God, how I hate advertisements with "up to" or "starting from"...

My employer's Internet connection is *guaranteed* to be 5 Mbit/sec in 
both directions at all times. (There are also contractual guarantees 
about how quickly the ISP will fix it if it breaks.)



How much do you pay for your broadband?

You *can* buy guaranteed bandwidth. It's just kinda pricey... ;-)

> (For the more conventionally minded resellers of used cars: we can safely 
> assume that any car can travel at speeds of up to 200 km/h, albeit briefly. 
> Just push it off the cliff of your choice.) 

For a sufficiently high cliff. And provided that the car's aerodynamic 
drag is insignificant compared to its mass at that speed... If it's a 
Robin Reliant, this is a dubious assumption.

Post a reply to this message

On 29/04/2010 10:01 PM, Invisible wrote:

>

> rate!
>
> On the other hand, if it takes 4 days to arrive, I just halved the
> transfer rate. And the latency is, of course, abysmal...
>
>
>
> I found the following quote on Wikipedia:
>
> "The theoretical capacity of a Boeing 747 filled with Blu-Ray discs is
> 595,520,000 Gigabits, resulting in a 37,034.826 Gb/s flight from New
> York to Los Angeles."
>
> Somebody bothered to compute this?!? o_O

Or as a uni lecturer said to my data comms class (circa mid 1980's):

"Never underestimate the bandwidth of a ute full of tapes speeding down 
the highway"

At the time we were learning about synchronous protocols operating over 
1200bps links.

Post a reply to this message

>> I found the following quote on Wikipedia:
>>
>> "The theoretical capacity of a Boeing 747 filled with Blu-Ray discs is
>> 595,520,000 Gigabits, resulting in a 37,034.826 Gb/s flight from New
>> York to Los Angeles."
>>
>> Somebody bothered to compute this?!? o_O
> 
> Or as a uni lecturer said to my data comms class (circa mid 1980's):
> 
> "Never underestimate the bandwidth of a ute full of tapes speeding down 
> the highway"

Heh, yeah!

> At the time we were learning about synchronous protocols operating over 
> 1200bps links.

I wonder... What's the bandwidth of a punch-card reader/writer?

Post a reply to this message

> Out of idle curiosity: have you actually measured data-transfer?

Several times, just last night I tried the BBC iPlayer diagnostic page and 
it gave me 5.8 Mbit/s.  In my modem settings page it says it's connected at 
60xx kbit/s usually.  Sometimes download speeds in windows go up to 600 
Kbyte/s, it depends on where it's coming from.  I guess the theoretical 
limit of my line might be 6 Mbit/s, but it would be a coincidence as my 
package is only for 6 Mbit/s.

> I pay for 6Mbit/s but get only 3Mbit/s.

That's like my dad, he pays for 8Mbit/s (AFAIK all BT packages in the UK 
offer 8Mbit/s) and only gets about 2.5 (according to the modem settings 
page).

Post a reply to this message

>> I pay for 6Mbit/s but get only 3Mbit/s.
> 
> That's like my dad, he pays for 8Mbit/s (AFAIK all BT packages in the UK 
> offer 8Mbit/s) and only gets about 2.5 (according to the modem settings 
> page).

Presumably the link-layer speed depends on the line. (AFAIK, a large 
part of the modem handshake process consists of testing the various 
frequency bands to see which ones are clear enough to be useable. That's 
what dictates your transfer speed.)

The amount of IP data you can transfer depends not only on the 
link-layer speed, but also the speed of the server you're talking to, 
how much congestion there is on the entire route between you and the 
server, how responsive your own PC is going, etc etc etc.

(And, of course, the amount of "real" data is the amount of IP data 
minus all the protocol overhead - IP headers, TCP headers, handshakes, 
retransmits, timeouts, etc.)

Post a reply to this message

TC wrote:
> God, how I hate advertisements with "up to" or "starting from"...

I always liked "Up to 50% off, or more!"

-- 
Darren New, San Diego CA, USA (PST)
   Linux: Now bringing the quality and usability of
   open source desktop apps to your personal electronics.

Post a reply to this message