I'm still on the hunt for a robust active-probing tool for VoIP providers. Does anyone have experience with the Tektronix PowerProbe 500 or 6000 probes? Are they still sold? Tektronix' sales literature is dated 2008. http://www2.tek.com/cmswpt/tidetails.lotr?ct=TI&cs=afs&ci=14603&lc=EN I want devices that can: (a) Register (b) Place and receive calls through an SBC. (c) Function properly behind NAT, with SBC help. (d) Place and receive POTS (two wire analog) calls, and report statistics through the network interface (e) Run calls on a schedule (which implies that remote probes connect in to get instructions.) (f) Report statistics on every call: (1) For VoIP calls, RTCP-XR -like-stats are good. (2) For POTS calls, eMOS / PESQ is nice, plus more precise measurements, such as signal-to-noise ratio, echo, audio round trip time, frequency-response spectrum, or other audio defects. Ideally, do all this with a Linux command-line interface for me and a pretty web interface for anybody who asks. mark at ecg.co | +1-229-316-0013 | http://ecg.co/lindsey