And how many apartments where covered by that single IP address? Was this where there is a restriction on other providers so the occupants had no choice of wireline ISP?
> On 23 Sep 2021, at 09:38, Colton Conor <colton.co...@gmail.com> wrote: > > Where does this "You can only have about 200-300 subscribers per IPv4 > address on a CGN." limit come from? I have seen several apartment > complexes run on a single static IPv4 address using a Mikrotik with > NAT. > > On Wed, Sep 22, 2021 at 2:49 PM Baldur Norddahl > <baldur.nordd...@gmail.com> wrote: >> >> >> >> On Wed, 22 Sept 2021 at 16:48, Masataka Ohta >> <mo...@necom830.hpcl.titech.ac.jp> wrote: >>> >>> Today, as /24 can afford hundreds of thousands of subscribers >>> by NAT, only very large retail ISPs need more than one >>> announcement for IPv4. >> >> >> You can only have about 200-300 subscribers per IPv4 address on a CGN. If >> you try to go further than that, for example by using symmetric NAT, you >> will increase the number of customers that want to get a public IPv4 of >> their own. That will actually decrease the combined efficiency and cause you >> to need more, not less, IPv4 addresses. >> >> Without checking our numbers, I believe we have at least 10% of the >> customers that are paying for a public IPv4 to escape our CGN. This means a >> /24 will only be enough for about 2500 customers maximum. The "nat escapers" >> drown out the efficiency of the NAT pool. >> >> The optimization you need to do is to make the CGN as customer friendly as >> possible instead of trying to squeeze the maximum customers per CGN IPv4 >> address. >> >> Perhaps IPv6 can lower the number of people that need to escape IPv4 nat. If >> it helps just a little bit, that alone will make implementing IPv6 worth it >> for smaller emerging operators. Buying IPv4 has become very expensive. Yes >> you can profit from selling a public IPv4 address to the customer, but there >> is also the risk that the customer just goes to the incumbent, which has old >> large pools of IPv4 and provides it for free. >> >> Regards, >> >> Baldur >> -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org
