From my experience, the Internet IP Transit Bandwidth costs ISP's a lot
more than the margins made on Broadband lines.So users who rarely use their connection are more profitable to the ISP.
The fat man isn't a welcome sight to the owner of the AYCE buffet.
What exactly does this imply, though, from a networking point of view?
... JG
> So users who rarely use their connection are more profitable to the ISP.
The fat man isn't a welcome sight to the owner of the AYCE buffet.
Joe,
The fat man is quite welcome at the buffet, especially if he brings
friends and tips well. That's the buffet's target market: folks who
aren't satisfied with a smaller portion.
The unwelcome guy is the smelly slob who spills half his food,
complains, spends most of 4 hours occupying the table yelling into a
cell phone (with food still in his mouth and in a foreign language to
boot), burps, farts, leaves no tip and generally makes the restaurant
an unpleasant place for anyone else to be.
What exactly does this imply, though, from a networking point of view?
That the unpleasant nuisance who degrades everyone else's service and
bothers the staff gets encouraged to leave.
Regards,
Bill Herrin
> > So users who rarely use their connection are more profitable to the ISP.
>
> The fat man isn't a welcome sight to the owner of the AYCE buffet.The fat man is quite welcome at the buffet, especially if he brings
friends and tips well. That's the buffet's target market: folks who
aren't satisfied with a smaller portion.The unwelcome guy is the smelly slob who spills half his food,
complains, spends most of 4 hours occupying the table yelling into a
cell phone (with food still in his mouth and in a foreign language to
boot), burps, farts, leaves no tip and generally makes the restaurant
an unpleasant place for anyone else to be.
However, if the sign on the door said "burping and farting welcome" and
"please don't tip your server", things are a bit different. Similar
comparisons to use of the word "unlimited" apply.
> What exactly does this imply, though, from a networking point of view?
That the unpleasant nuisance who degrades everyone else's service and
bothers the staff gets encouraged to leave.
Until it is generally considered common courtesy (and recognised as such
in a future edition of "Miss Manners' Guide To The Intertubes") to not
download heavily for fear of upsetting your virtual neighbours, it's
reasonable that not specifically informing people that their "unpleasant"
behaviour is unwelcome should imply that such behaviour is acceptable.
- Matt
But the fat man isn't allowed to take up residence in the restaurant
and continously eat - he's only allowed to be there in bursts, like we
used to be able to assume people would use networks they're connected
to. "Left running" P2P is the fat man never leaving and never stopping
eating.
Regards,
Mark.
ffs, stop with the crappy analogies.
The internet is like a badly designed commodity network. Built increasingly
cheaper to deal with market pressures and unable to shift quickly to shifting
technologies.
Just like the telcos I recall everyone blasting when I was last actually
involved in networks bigger than a university campus.
Adrian
I think no matter what happens, it’s going to be very interesting as Comcast rolls out DOCSIS 3.0 (with speeds around 100-150Mbps possible), Verizon FIOS expands it’s offering (currently, you can get 50Mb/s down and 30Mb/sec up), etc. If things are really as fragile as some have been saying, then the bottlenecks will slowly make themselves apparent.
-brandon
I think no matter what happens, it's going to be very interesting as Comcast
rolls out DOCSIS 3.0 (with speeds around 100-150Mbps possible), Verizon FIOS
Well, according to wikipedia DOCSIS 3.0 gives 108 megabit/s upstream as opposed to 27 and 9 megabit/s for v2 and v1 respectively. That's not what I would call revolution as I still guess hundreds if not thousands of subscribers share those 108 megabit/s, right? Yes, fourfold increase but ... that's still only factor 4.
expands it's offering (currently, you can get 50Mb/s down and 30Mb/sec up),
etc. If things are really as fragile as some have been saying, then the
bottlenecks will slowly make themselves apparent.
Upstream capacity will still be scarce on shared media as far as I can see.
> But the fat man isn't allowed to take up residence in the restaurant
> and continously eat - he's only allowed to be there in bursts, like we
> used to be able to assume people would use networks they're connected
> to. "Left running" P2P is the fat man never leaving and never stopping
> eating.ffs, stop with the crappy analogies.
They're accurate. No network, including the POTS, or the road
networks you drive your car on, are built to handle 100% concurrent use
by all devices that can access it. Data networks (for many, many years)
have been built on the assumption that the majority of attached devices
will only occasionally use it.
If you want to _guaranteed_ bandwidth to your house, 24x7, ask your
telco for the actual pricing for guaranteed Mbps - and you'll find that
the price per Mbps is around an order of magnitude higher than what
your residential or SOHO broadband Mbps is priced at. That because for
sustained load, the network costs are typically an order of magnitude
higher.
The internet is like a badly designed commodity network. Built increasingly
cheaper to deal with market pressures and unable to shift quickly to shifting
technologies.
That's because an absolute and fundamental design assumption is
changing - P2P changes the traffic profile from occasional bursty
traffic to a constant load. I'd be happy to build a network that can
sustain high throughput P2P from all attached devices concurrently - it
isn't hard - but it's costly in bandwidth and equipment. I'm not
against the idea of P2P a lot, because it distributes load for popular
content around the network, rather than creating "the slashdot effect".
It's the customers that are the problem - they won't pay $1000 per/Mbit
per month I'd need to be able to do it...
TCP is partly to blame. It attempts to suck up as much bandwidth as
available. That's great if you're attached to a network who's usage is
bursty, because if the network is idle, you get to use all it's
available capacity, and get the best network performance possible.
However, if your TCP is competing with everybody else's TCP, and you're
expecting "idle network" TCP performance - you'd better pony up money
for more total network bandwidth, or lower your throughput expectations.
Regards,
Mark.
At the risk of incurring Mr. Pilosoft’s wrath (the Putin of NANOG?), I’ll looking for NANOG style ISP meetings to attend in Europe this year (France, Germany, UK, Belgium, and Netherlands). Any suggestions would be appreciated. Please bypass the list and send them directly to me.
Roderick S. Beck
Director of European Sales
Hibernia Atlantic
1, Passage du Chantier, 75012 Paris
http://www.hiberniaatlantic.com
Wireless: 1-212-444-8829.
Landline: 33-1-4346-3209.
French Wireless: 33-6-14-33-48-97.
AOL Messenger: GlobalBandwidth
rod.beck@hiberniaatlantic.com
rodbeck@erols.com
``Unthinking respect for authority is the greatest enemy of truth.’’ Albert Einstein.
This is amazing. People are discovering oversubscription.
When we put the very first six 2400bps modems for the public on the
internet in 1989 and someone shortly thereafter got a busy signal and
called support the issue was oversubscription. What? You mean you
don't have one modem and phone line for each customer???
Shortly thereafter the fuss was dial-up ISPs selling "unlimited"
dial-up accounts for $20/mo and then knocking people off if they were
idle to accomodate oversubscription. But as busy signals mounted it
wasn't just idle, it was "on too long" or "unlimited means 200 hours
per month" until attornies-general began weighing in.
And here it is over 18 years later and people are still debating
oversubscription.
Not what to do about it, that's fine, but seem to be discovering
oversubscription de novo.
Wow.
It reminds me of back when I taught college and I'd start my first
Sept lecture with a puzzled look at the audience and "didn't I explain
all this *last* year?"
But at least they'd laugh.
Hint: You're not getting a dedicated megabit between chicago and
johannesburg for $20/month. Get over it.
HOWEVER, debating how to deal with the policies to accomodate
oversubscription is reasonable (tho perhaps not on this list) because
that's a moving target.
But here we are a week later on this thread (not to mention nearly 20
years) and people are still explaining oversubscription to each other?
Did I accidentally stumble into Special Nanog?
I'm not aware of MSOs configuring their upstreams to attain rates for 9 and
27 Mbps for version 1 and 2, respectively. The numbers you quote are the
theoretical max, not the deployed values.
Frank
But with 1000 users on a segment, don't these share the 27 megabit/s for v2, even though they are configured to only be able to use 384kilobit/s peak individually?
Except that upstreams are not at 27 Mbps
(http://i.cmpnet.com/commsdesign/csd/2002/jun02/imedia-fig1.gif show that
you would be using 32 QAM at 6.4 MHz). The majority of MSOs are at 16-QAM
at 3.2 MHz, which is about 10 Mbps. We just took over two systems that were
at QPSK at 3.2 Mbps, which is about 5 Mbps.
And upstreams are usually sized not to be more than 250 users per upstream
port. So that would be a 10:1 oversubscription on upstream, not too bad, by
my reckoning. The 1000 you are thinking of is probably 1000 users per
downstream power, and there is a usually a 1:4 to 1:6 ratio of downstream to
upstream ports.
Frank
At the risk of incurring Mr. Pilosoft's wrath (the Putin of NANOG?), I'll
he's not a bad guy actually 
it's a rough job corralling all the
-admin folks I'm certain. Also this isn't really that off topic is it?
looking for NANOG style ISP meetings to attend in Europe this year (France,
Germany, UK, Belgium, and Netherlands). Any suggestions would be
RIPE? In berlin in May:
http://www.ripe.net/ripe/meetings/ripe-56/index.html
-Chris
At the risk of incurring Mr. Pilosoft's wrath (the Putin of NANOG?),
You meant the "srh of nanog". And I'm not 
I'll looking for NANOG style ISP meetings to attend in Europe this year
(France, Germany, UK, Belgium, and Netherlands). Any suggestions would
be appreciated. Please bypass the list and send them directly to me.
The first thing that comes to mind is RIPE. Next thing that comes to mind
is UKNOF.
Also, that isn't really off-topic. However, if you get off-list replies,
could you please do a follow-up summary post and list the european neteng
groups, that would be quite helpful. A good starting point for the search
is www.euro-ix.net, which lists european IXPs. Many IXP's have annual (or
more often) meetings of members, which serve similarly to NANOG. See:
https://www.euro-ix.net/news/meetevent/ for starters.
-alex
Except that upstreams are not at 27 Mbps
(http://i.cmpnet.com/commsdesign/csd/2002/jun02/imedia-fig1.gif show that
you would be using 32 QAM at 6.4 MHz). The majority of MSOs are at 16-QAM
at 3.2 MHz, which is about 10 Mbps. We just took over two systems that were
at QPSK at 3.2 Mbps, which is about 5 Mbps.
Ok, so the wikipedia article <http://en.wikipedia.org/wiki/Docsis> is heavily simplified? Any chance someone with good knowledge of this could update the page to be more accurate?
And upstreams are usually sized not to be more than 250 users per upstream
port. So that would be a 10:1 oversubscription on upstream, not too bad, by
my reckoning. The 1000 you are thinking of is probably 1000 users per
downstream power, and there is a usually a 1:4 to 1:6 ratio of downstream to
upstream ports.
250 users sharing 10 megabit/s would mean 40 kilobit/s average utilization which to me seems very tight. Or is this "250 apartments" meaning perhaps 40% subscribe to the service indicating that those "250" really are 100 and that the average utilization then can be 100 kilobit/s upstream?
With these figures I can really see why companies using HFC/Coax have a problem with P2P, the technical implementation is not really suited for the application.
The wikipedia article is simplified to the extent that it doesn't embed
actual practices. Those are best obtained at SCTE meetings and discussion
with CMTS vendors.
A 10x oversubscription rate from residential broadband access doesn't seem
too unreasonable to me based in practice and what I've heard, but perhaps
other operators have differing opinions or experiences.
The '250' is really 250 subscribers in my case, but you're right, you see
different figures bandied about in regards to homes passed and penetration.
Frank
