This article from Frost & Sullivan explains the challenges of using VoIP (Voice over IP) for telephone services. As of 2007 about 50% of companies surveyed were planning to substitute VoIP for switched telephony services. Although costs may be lower and flexibility increased, more responsibility rests on the company to ensure quality of service and availability. VoIP telephone service is sharing the same path and bandwidth as data traffic. Also, more responsibility rests at the periphery of the network with the company than with a switch that may be maintained by a telephone company.