Two users share their hard-learned tips for deploying centralized VoIP. Lehman Brothers: Easier disaster recovery Master Financial: Strong business lessons As a consumer of financial services, you probably couldn't care less whether your stockbroker is talking to you over\u00a0VoIP\u00a0or that the loan officer processing your mortgage application uses a PC-based softphone instead of a desktop handset. But to the purveyors of such services, this behind-the-scenes technology is making all the difference in the world for their operations. By placing IP PBXs in the new\u00a0data center\u00a0and turning voice into just another IP application, financial services firms are cutting costs on equipment, traditional voice services and telecom management. At the same time, they're becoming more flexible and efficient.VoIP experts at two such firms - global financial powerhouse\u00a0Lehman Brothers and\u00a0Master Financial , a home-loan-approval firm - tell us what they've learned along the way.