ServiceNetworks

Hello all, I'm a noob. I'm using IVM and like the product. I have corporate broadband, however sometimes the phone calls are choppy when I make phone calls using VOIP (in instances where I try to make multiple calls at the same time). I do have a dedicated machine running IVM so I'm not too worried about other processes running, I believe it's the bandwidth. What I'm pretty sure is happening is that other internet users (grrrrr ) are sucking up my upload bandwidth . I would like to set QoS Quality of Service on my router to a priority level for my VOIP calls. When I first installed the software I remember it saying something like "IVM is going to open a bunch of ports" but I'm not sure which ones it uses to place the VOIP calls. Does anyone know which ports I should boost the priority on? Thanks for your help in advance.