[ale] [OT] AT&T/UVerse going to carrier grade NAT?

[Brian Mathis]

On Fri, Jun 8, 2012 at 3:57 PM, Derek Atkins <warlord at mit.edu> wrote:
> Stephen Haywood <stephen at averagesecurityguy.info> writes:
>> You can do a /30, which would mean the customer gets one IP.
>
> You're assuming you give the customer a subnet.  You don't have to do
> that.
>
> You can do what Comcast residential does which is have a /22 (IIRC)
> shared network amongst all of the area and gives out singleton addresses
> to each customer on the network.  So you get a single IP as part of the
> /22 for your registered host.  You're broadcast network is your entire
> local loop, however the cablemodem does blocking to make sure you don't
> see your neighbor's traffic.  Your gateway is effectively the head-end;
> the cablemodem acts as a bridge.
>
> Cable companies have been operating that way for years!  Why dole out
> four IPs per customer when you can just give out one?
>
> -derek



I would guess that most people who want a static IP are businesses, so
to simplify the product line and support they use small subnets
instead of schemes like this.  In this sense, the telecom networks
seem to be more "pure" than the cable ones.


❧ Brian Mathis