RE: IPv6 NAT

Joe Abley wrote: There's no useful way to use H.323 through a NAT though, at least that I have seen working.

In enterprises this has never been a problem as H.323 works fine over any kind of tunnel that goes over NAT and that's already there for other purposes (VPN for example). I have multiple h.323 VOIP phones at home over one IP address, one that is actually IPSEC encrypted. As of SIP, Vonage does indeed use it so are many other SIP shops and it works fine over NAT Vonage or not Vonage. I am not that familiar with the Cisco ATA-186 (too pricey) but on other SIP phones such as the popular $70 Grandstream if you know the IP address and port of the remote SIP phone you want to join you can dial it directly. Michel.