Don't worry about the type or volume of calling, instead focus on the calling patterns. At the end of the day, they really won't care what you are sending through, they are making money off it. One reliable provider states: "Customers generating more than 500 daily call attempts will be subject to the following requirements for NANPA (USA/CANADA) calls: a) Minimum 45-second Average Length of Call (ALOC) Minimum 70% Answer to Seizure Ratio (ASR) c) Maximum 20% of traffic under 6 seconds in duration" If you are e.g. wardialing or robocalling sequential numbers the problem is going to be your ALOC and calls under 6 seconds duration. What is your expected call volume? I might have some suggestions.