Re: Are we really running out of IPv4?
> There are not even enough IPv4 addresses for all the mobile devices.
Does that really matter? We have IPv6 and ways of using IPv4 over the IPv6 carrier service.
Okay it means websites etc probably need to run dual stacks and some way for phones (IPv6 end points) to accept and correctly connect to explicit IPv4 public addresses.
Given the experience of the mobile telcos with 4G/IPv6, perhaps we can expect one of the fixed line ISPs to go IPv6 only, with their router handling the IPv4 over IPv6….
> NAT breaks things.
Depends on what you mean, the original RFC for NAT and the subsequent one for NAPT contain guidance for FTP and ICMP. Okay the solution isn’t elegant etc., but a workable solution was presented. I suspect many of the problems people experienced were more to do with poor implementations of NAT & NAPT (and thus the implementation of the FTP packet header rewriter) although the level of detail in the relevant RFCs does leave much to be desired…
>VoIP
I suggest NAT doesn’t actually break VoIP, it was more the VoIP designers only considering a specific “more purist” view of the Internet and so didn’t concern themselves with designing for NAT and NAPT, even through these technologies would have been widely used in the client environment at the time the VoIP experts were drawing up their RFCs…
> just to get around the address shortage.
NAT did more than this. Remember prior to the ready availability of Internet access, many office networks ran TCP/IP, mostly using the private address ranges (specifically 192.168..). NAT permitted these networks to be readily connected to an ISPs service and gain access to the public Internet. Subsequently, it has made it easy switch ISPs.
From memory, it took a bit of a rebellion for IPv6 to take account of such real world considerations, becoming better because of it.