You have a few factors to consider when determining how many concurrent calls 1 line can have. As an example 1 full feature line with voice mail could be engaged in a call, a call waiting, and a third call routing to voice mail. Effectively that like could take 3 concurrent calls. On the other hand our BVE numbers have access to many more features like call parking, call transfer, and hunt-group, to name a few. These in combination with the number of lines you have, allow for a much larger number of concurrent calls to your location. If you are having an y issues with your services feel free to send me a private message for more support.