Quite simply, quality matters. Voice over IP is now a mature, proven technology which is becoming increasingly common as organisations seek to benefit from the lower infrastructure and communications costs and productivity-enhancing call services that VoIP can provide. In this new era of convergence, a business must ensure that any solution delivers existing functionality (at a comparable level of service) whilst exploiting all the associated opportunities that voice and data over one (IP) environment can deliver - for example VoIP solutions and presence management.
At the same time any solution must be future proofed to ensure investment is fully leveraged in the long term. A business must correctly balance the business/employee benefits against all the potential issues. Most important are 'Voice' and 'Data' quality.
Voice calls and latency dependant data traffic require an assured level of quality and security for business use
Whist Voice over the Internet is starting to take off down to the potential cost savings (e.g. Skype), many users do not talk to customers over such a service. Voice calls over an IP infrastructure (e.g. an IPVPN) is a business grade alternative and a broadband connection (QoS enabled) to a VPN can enable this extremely cost effectively.
For more information see Is broadband 'business grade'?