I have currently been assigned with starting the implementaion of moving in the direction of VoIP over my wan. My current phone system at the core of my network is a siemens. It has IP capabilities, but I am very unfamiliar with it. Bascially we want the whole four digit dialing deal over the wan. I have installed 2800 series routers in all of my remote sites in prep for this. Is it going to be easier for me to just install voice modules in these routers to do this? or to use my existing pbx to do trunking? I am very confused on where to even begin my research.