[AusNOG] SMH: "No room at the internet"

[Matthew Moyle-Croft]

On 20/05/2010, at 12:56 PM, Kevin Karp wrote:

> Hi David
> 
> >Most users need very few ports, ...
> 
> Very true, but even a few ports can hurt a lot. 

For the ISP world we're not talking much overloading for CGNAT.   My view is that if you can achieve a 1:2 or 1:4 utilisation of IPv4 addresses then that buys you a lot of time to get to a point where v4 connectivity is just a "need to make things work occasionally".   In that kind of world each "service" can get, say, 16000 odd ports ((2^16)/4) and pretty much live an okay life providing that IPv6 starts to take it's share of the load.   Even at a 1:8 ratio we're talking ~8000 ports/service.  

My hope is that our ubeaut BRAS can do the CGNAT inside rather than having to have a separate box to do it.   ie.  IP Pools become just a bit smarter -> not just 32bits of IP, but a few more bits for the top part of the port #.

As Kevin points out with GMaps -> if that's moved to IPv6 then the CGNAT load drops a lot.   

But, if IPv6 isn't on the uptake quickly then the world will suck hard for those stuck with IPv4.

My worry at the moment, other than ADSL CPE, is convincing the CDN providers (Akamai, et al) to make the move.   If they don't, then iTunes can't (for example) and we go back to the suck hard bit.

MMC