er companies that might not have in- house expertise to manage e-mail, UC, and IP telephony. These companies might also be uncertain about their future growth. In addition, hosted systems provide disaster recovery and portability. If the customer loses electricity or their LAN crashes, they can access their e-mail and telephony functions remotely. VoIP hosting providers include 8x8, Inc., PingTone, and MegaPath, as well as telephone companies and cable providers such as Cablevision Systems and Cox Communications. Managing Customer Relationships by Using Contact Centers Contact centers are groups of agents created to handle incoming and outgoing sales, web queries, credit and collections, and customer service queries. Contact centers con- sist of software on servers that is used to manage incoming and outgoing communica- tions with agents, particularly when there are more calls and other messages than there are people to respond to them. Importantly, contact centers provide statistics on utiliza- tion of agents, telecommunications lines, and numbers of e-mail and chats. The main theory behind grouping agents into "pools" is that large groups of agents can handle more calls than the same number of agents organized into small groups, without overflow of calls between groups. This is analogous to the practice of the United States Post Office of using one long line for postal clerks rather than an Data Centers and IP Private Branch Exchanges individual line for each. With one line for all postal workers, a clerk will be available more quickly from the pool and the same number of clerks will help more people within a given amount of time than by forming separate lines for each clerk. Contact centers route incoming calls to the agent that has been idle the longest within the appropriate agent group, based on the telephone number dialed or by the customer's account or telephone number. If all agents are busy, the contact center shunts the call to a queue, routes the call to an alternate group of agents, or gives the call