I am working for a complete Network solution for a University campus for voice, data and video facilties for 1000 users. I would like to use VOIP for voice. This is a single campus with 22 departments conneted thru Cisco switch using Gigabit fiber backbone using VLAN etc. This network will be connectd to PSTN for outside connectivity. Can you kindly suggest me what are the equipments reuired for VOIP implementation. Right now Gigabit LAN is implemented. What additional cisco equipments, Servers, Softwares etc needed for implemeting VOIP isde this company, will it be cost effective compared to traditional PBX system?. Right now they dont have any voice facilties.