Until recently, soft phones could not function on the thin client device or in thin client architectures. This is because the sound media is converted into physical digital sound on the computer in the IT data center, physically a long distance from the user's thin client device display and speakers. This is a problem even on a high-speed network because the actual sound content is many times larger than the super-compressed content transmitted digitally over the Internet. This would be like connecting a garden hose on a fire hydrant; very little of the data will actually reach the end-user.

However, if the soft phone is running in a virtual PC, such as with the VPCC system from NEC, the soft phone data is not converted on the back-end server, due to the filtering solution provided by NEC's US100 thin clients. Instead, the voice data remains encoded and is efficiently transferred to the US100 thin client device over the network. The US100 includes necessary codex for decoding video and sound content. In the case of the soft phone, the encoded sound is decoded by the US100 providing full voice quality. Additionally, the US100 can maintain peer to peer telephony communication thereby reducing bandwidth and providing further efficiencies on for the VPC Virtual PC Server.

The benefits of the VPCC solution with integrated telephony are: