Dear Duane, As far as I know from working with the Deutsche Bundespost / Deutsche Telekom the Metering tone is generated by a generator with +- 200 ohms internal impedance. Switching it on and off is done (at least in the test setup) by a relay, so there is no nice exponential rise, or 0 phase start. Deutsche Telekom procurement lab claimed that they test it that way because that's how the actual network works.
Best regards, Rene
