Aswath, I fully agree with you. The plugtest is not reliable. But what is also not reliable is the requirement from the FCC that VoIP providers not connected to the PSTN need not to provide access to emergency services. Finally any device connected to the Internet must provide access to emergency services, because otherwise there would be no emergency services if the PSTN runs out. But this cannot be solved within some month. See also my comment to Martin.

Even though the recent ruling is billed as a requirement on VoIP service providers, this will turn out to be solely a requirement on the incumbents that IF a VoIP service provider requests access to E911 network, then such a request must be granted.

For more reason than this, I hope that PSTN will not run out.

It has to, because in some years nobody can afford to run it, for less and less subscribers. Also the incumbent manufacturers will not ba able to support it any longer. There is also no experts left, not with Telcos and not with manufacturers. They either left the company to do something more interesting (guess what) or are retired. Do a head count in any telco on SS7 specialists. If you need two hands it is a very large telco.

Both ETSI TISPAN and ATIS are currently spezifying the NGN subsystems PSTN emulation and PSTN simulation. This sounds very much like PSTN replacement.