The PAP2T was set-up according to 2talk's instructions, but I have had to enable NAT to get incoming calls working every time (as suggested by 2talk support).
But the sound quality is nowhere near as good as the land-line.
I have searched this forum and made several changes that are recommended, but none improved the sound quality. I have tried an analogue phone as well as a DECT cordless phone.
The changes I have tried include
FXS port impedance
FXS input and output port gains
turning off echo cancelling/suppression
increasing the priority of router port used by the PEP2T.
I would describe the sound as crackly, but its not a crackle on top of the speech, its more like a radio when its just off the station.
Any suggestions of anything else I can try.