[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: adsl keep alive script



Hi

Again, I must say that I work for Netvision (please do not flame ;-)
Please see my comments inline.

Arie

> -----Original Message-----
> From: Nadav Har'El [mailto:nyh@math.technion.ac.il] 
> Sent: Saturday, December 01, 2001 2:15 AM
> To: guy keren
> Cc: Ghiora Drori; linux-il
> Subject: Re: adsl keep alive script
> 
> 
> On Sat, Dec 01, 2001, guy keren wrote about "Re: adsl keep 
> alive script":
> > charging money is one way to limit the number of users who 
> want to get 
> > a limited resourec. and IP addresses are a limited resource 
> (even if 
> > its an artificial limit, due to someone once thinking 
> 'well, 32 bits 
> > should be enough for everybody' ;)  ).
> 
> This is quite irrelevant, since ADSL users typically leave 
> their ADSL connection on 100% of the time. Or, if they only 
> turn on their computer some of the day, they all tend to do 
> it on the same time. The end result is that an ADSL provider 
> probably (and I didn't check this with actual
> statistics) needs almost as many IP numbers as it has 
> customers - even if these are not fixed IPs.
> 
I am sorry to tell you, but you are quite wrong here...


> Users which only log in infrequently probably don't get ADSL 
> - unless they are rich and don't mind throwing away money.
> 
> The only benefit of non-fixed IPs that I can see is lower 
> administration effort (no need to remember which IP belongs 
> to whom) and easier renumbering, if the ISP decides to move 
> its ADSL block to a different address block.
> 
The other benefit is that the ISP can make his routing table smaller,
avoiding using host routes for each and every user, and being able to
aggregate the larger pools of IPs allocated to users on demand.


> > in fact, i'd expect providers to start NATing their ADSL users, if 
> > their number grows too far and large. otherwise, i don't see how 
> > millions of ADSL/cable/fixed-line connections could be 
> supported, and 

Doing NAT on a large scale basis is a difficult task, and is not a
really good solution. I guess you wouldn't have liked being connected
behind a NAT connection, wouldn't you?

> > i don't see ipv6 actually coming in any time soon (i.e. withing the 
> > next 3-4 years).
> 

As it seems, IPv6 is being pushed quite hard by companies like Cisco,
and extensive testing is being done. I already heard about commercial
providers using it with a subset of customers.

I think that it will be used sooner by providers who need it's features
(i.e. lot's of IP addresses).
The main reason it is hard to deploy IPv6 (except that people are not
familiar with it) is that the hosts (PCs) lack the easy support for it
(like they have for IPv4).
I think this is about to change...

> Maybe MIT can return some of the 16 million addresses (a 
> class A) it now controls? Same goes for Apple, and many other 
> organizations. The American DoD controls much more than that, 
> and I doubt it uses more than 1/1000 of the addresses it owns...
> 
> I don't think we'll be running out of IP space in the next 5 
> years. Running out of AS numbers (16 bit only), and a return 
> to exponential growth of routing tables (after CIDR managed 
> to keep the growth linear for several
> years) seem like more immediate problems.
> 
> Of course, it doesn't mean we should start giving global IPv4 
> addresses to every refrigerator and cellphone on the planet...
> 
> -- 
> Nadav Har'El                        |    Saturday, Dec  1 
> 2001, 16 Kislev 5762
> nyh@math.technion.ac.il             
> |-----------------------------------------
> Phone: +972-53-245868, ICQ 13349191 |You have the right to 
> remain silent.
> http://nadav.harel.org.il           |Anything you say will be 
> used against you.
> 
> =================================================================
> To unsubscribe, send mail to linux-il-request@linux.org.il 
> with the word "unsubscribe" in the message body, e.g., run 
> the command echo unsubscribe | mail linux-il-request@linux.org.il
> 
> 

To unsubscribe, send mail to linux-il-request@linux.org.il with
the word "unsubscribe" in the message body, e.g., run the command
echo unsubscribe | mail linux-il-request@linux.org.il