The biggest disadvantage of packet switching, which transfers digital information in discrete blocks rather than in a continuous stream, is having data arrive in bundles that must be reassembled at the reception point. When packets are routed through various network adapters, buffers and switches, they can arrive at their destination out of their original sequence. This makes the technology less than ideal for applications such as voice-over-Internet.
An alternate method of delivering data is circuit switching, which requires a point-to-point and continuous connection between transmission and reception. An example of circuit switching is the telephone call. Packet switching is cheaper because the user pays a fee per unit of data while circuit switching is charged by connection time. For this reason, packet switching is preferred for transmitting data while circuit switching is the preferred method for voice.
The biggest impediments to packet switching for voice applications are latency (delay) and poor voice quality, because packets containing voice signals can arrive at the destination (listener) at various times and out of order. With packet switching, blocks of data seek the most efficient routes for transmission as circuits become available, which is economical for transmitting large amounts of data. The Internet is based on packet switching, but most corporations have a hybrid system employing both methods of transmission.