On Thu, 2003-08-07 at 21:00, Pekka Savola wrote: > Hi Mark, > > Thanks for the long reply; I found it very interesting.
Thanks for reading it. A few more > comments in-line.. > > (hopefully this won't drift too far off-topic..) > Hopefully. > On 7 Aug 2003, Mark Smith wrote: > > On Thu, 2003-08-07 at 17:47, Pekka Savola wrote: > > > On Thu, 7 Aug 2003, Andrew White wrote: > > > > > Just responding to a few points.. > > > > > > <snip> > [...] > > Since the realisation that dial-up was a dying technology, a lot of the > > dial up ISPs are providing ADSL, wholesaling it from Telstra. According > > to this page (http://www.broadbandchoice.com.au/isp-list.cfm), there are > > currently 149 residential ISPs in Australia, which is probably quite a > > lot for a country with only 20 million or so people. > > Ok, that's a lot: how many of these is typically available in a > geographical area? That is, when you live in city X, how many possible > ISP's are there? > There are only 8 major cities in Australia, with the majority of the population living in them. I live in Adelaide, which as a population of about 1.2 million people, the forth largest city after Sydney, population 4 million. According to the Adelaide page on at the same site (http://www.broadbandchoice.com.au/), there are 97 ISPs ! (I'm a little surprised ... that is a lot.) A number of them are "national" though, pretty much only because they use Telstra's national ADSL network. > That is, do the ISPs have any incentive to be competitive about the > customers? > You'd think :-) It seems that most of them follow Telstra's retail product lead - there isn't all that much difference between plans. Most of the smaller ISPs seem to win and / or keep business because of better, more responsive customer service, not product differentiation. There seems to be enough demand that maintaining the status quo is a good business plan. > I.e. if one ISP provided static addresses "for free" (or something) but > still the regular bandwith caps, would that possibly spark some interest > for people to change to that model (and in turn, perhaps encourage the > other ISPs to also change their IP assignment model..) > I don't think so. Some of them are, it doesn't seem to have made much of a difference. I'm under a contract at moment, and fixed IPv4 addresses has only been introduced within roughly the last 12 months. For those of us that care about running a server, primarily in my case an SMTP server, the dynamic dns services are a pretty effective work around. Initially I didn't like the idea of dynamic dns, then I though "hey, IPv6 is designed with the assumption of changing network layer addresses, so as long as the domain name stays constant, the IPv4 address changing occasionally shouldn't matter that much either" :-) I've had some concerns email not being delivered because I dropped off of the net temporarily due to an IPv4 address change, but sending SMTP servers will try to deliver incoming mail for a few days, I should be back up and running within that time period. > > A typical residential ADSL service is : > > > > * Single IPv4 address, so you have to use NAT if you want more than one > > machine (although at least one enlightened ISP allows up to 8 PPP(oE|oA) > > logins at once on a single ADSL service) > > This is no problem in itself (IMO).. > I don't know, we all know how NAT is breaking the Internet :-) I follow and contribute to the Networking forum (plus a few others) on this web site (http://forums.whirlpool.net.au/), it is quite common to see people asking how they get their p2p apps working through their NATting ADSL routers. (as a related side note, have a read of this thread for an example of what a commonly known ADSL router vendor is telling their end-users about IPv4 NAT - http://forums.whirlpool.net.au/forum-replies.cfm?t=103689) > [...] > > * The single IPv4 address can change over time. Most ISPs don't specify > > the time period, and it varies, but I expect that having the same single > > IPv4 address for a week is starting to be an an exception, rather than a > > rule. > > .. but this might be. > > Do all (or most) of the ISPs changing the address also provide "premium" > static IP service? > Usually those ISPs call them their "Business ADSL" plans. > I assume your home PC (based on your description) is always on, so that > these changes are not causes by e.g. reboots or DHCP lease expirations? > I'd guess most of the time it is ISP policy, sometimes equipment reboots at their end. > [snip a lot of interesting detail] > > A lot of these ISPs also want to provide business ADSL over the same > > wholesaled ADSL infrastructure. They typically do this by : > > > > * Guaranteeing a single IPv4 address, that won't change. > > > > * Optionally routing a prefix for the customer LAN ie. no NAT. > > > > A lot of small business customers probably don't take this up, probably > > because they are told about the "security" using NAT. I'd suspect in > > most cases not having to change internal IPv4 addressing is not even a > > "NAT or not" consideration. > > Is it significantly more costly to obtain e.g. the static IPv4 address as > a premium service? For homes? > Most ISPs don't offer that service at all or will tell you to buy one of their business ADSL services. Looking at four of the more major ISPs in Adelaide, only one allocates a static IPv4 address, but their plans are not very good value for money. Compared to the plan I'm on at the moment, it would cost me 30% more ie. $30 more, with 1000MB of less data download a month. Since the dynamic dns solution is working pretty well for me, I probably would not be prepared to pay that extra 30%, even though I'd like to have a fixed IPv4 address. (I'm realising I'm slightly out of touch with the market regarding nobody giving static IPv4 address, when you are under a contract for a period, you don't bother looking at it too hard). > > > Note: consider how many of these techniques are used to prevent people > > > from keeping servers at their home systems (i.e., does the ISP consider > > > the changing address a bug or feature). > > > > Certainly a feature. > > > > ISPs quickly learnt not to filter incoming TCP / UDP ports to prevent > > people running "servers", http or otherwise, so they use the reliability > > of the single IPv4 address they allocate as a dis-incentive to running a > > "server". > > One might be able to make up a few legimate reasons for unnecessarily > changing IP addresses, but I think the real reason is possibly the > business case, I agree. and developing IPv6 might not actually help the situation > that much.. > If they are using limiting the number and the stability of IPv4 addresses as a significant product differentiater between residential and business products, RFC3117 recommended /48 allocations, and even the /64 allocations are a big dis-incentive to deploying IPv6 to their customers. > > > Also consider how the situation > > > would change (if any) with IPv6 provided by the ISP. > > > > > > > I'd suspect they would probably allocate periodically changing /128s to > > their residential ADSL users. > > Let's hope not. > > > > Real example: at home, I use DHCP on DSL to get addresses. During 1 year, > > > the addresses have changed _once_ (the ISP changed the prefix from which > > > it allocated the DSL users' addresses). That's good enough for me, and I > > > even manually glue all the IPv4 and resulting 6to4 addresses in my > > > configuration files, filters etc. > > > > So what is the weather like in Finland ? I might consider moving :-) > > At the moment it's nice, but Winters here are _real_, not like there Down > Under... :-) > You're talking to a man who has never *actually* seen snow, other than on the television. Closest I've come to it is the freezer :-) The coldest day I can remember in the last 15 years or so was 9 degrees celcius. Now that was _cold_ ! :-) Regards, Mark. -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
