How Big Is Your Call Center's Phone Bill?

The book "Call Center Benchmarking", from Purdue University's Center for Customer-Driven Quality, notes that telecommunications costs historically average 25% of total call center costs, while IT and telephone systems can run 15-25%.  VoIP makes possible radical changes in the former cost category.  Now, the advent of the open-source Asterisk PBX pushes the cost envelope in the latter category.  According to Brian Capouch, a leader in the Asterisk project, TCO for Asterisk-based implementations can run 15-20% of traditional PBX-based costs.  Integrators using Asterisk have scaled it to call centers as large as 5-10k seats/ reps.  Some have even pushed as far as merging it with SugarCRM, the open-source CRM platform that is also gaining traction.  Brian was recently interviewed on IT Conversations; if you pay the phone bill at your company this is worth listening to.  More interesting:  changing economics of call center technology changes the economics of the human vs. self-service tradeoff...