Those new to Voice, both traditional and the oIP type, might like this article on how it all works. http://www.oreillynet.com/pub/a/etel/2006/02/07/telecom-terms-and-concepts.html Shameless self promotion aside, the O'Reilly etel blog is a pretty interesting read. Sean -- Sean Walberg <sean at ertw.com> http://ertw.com