Dear Fem Osiyemi,
You can try at huge number of web sites available for VoIP. Big companies like http://www.lucent.com (an R&D) of AT&T Labs.
http://www.ietf.com etc are more knowledgable.
Gain more information on the ideas related to VoIP and discuss with people in the field.
I have few informations with me related to VoIP in bandwidth allocation, call addmission, delay etc.