e processing, data entry occurs online, so, in essence, data is transmitted only when you press the Enter key, but when you're looking at the screen or filling in a spreadsheet, nothing is being trans- mitted. Thus, interactive processing involves a traffic stream that's described as being bursty in nature, which implies long connect times but low data volumes. Therefore, interactive processing does not make efficient use of circuit-switched links: The connection would be established and held for a long period of time, with only little data passed. Packet switching was developed to increase the efficiencies associated with bursty transmission. Packet switching involves the multiplexing of multiple packets over one virtual circuit (i.e., the end-to-end logical connection that creates a complete path across the network from source to destination node; see Chapter 1, "Telecommunications Technology Fundamentals"). It also involves decentralizing the network intelligence-not only the intelligence for maintaining and tearing down the connections in centralized switches but also the endpoints that participate in the control of the end-to-end session. Packets A packet is basically a container for bits. We also use terms such as blocks, frames, cells, and datagrams to depict the same general concept, although there are differences in what type of information each contains. A packet can be a number of sizes, contain different numbers of bits, and have varying amounts of navigational control that the network nodes can use to navigate and route the packet. (Chapter 7 discusses some of the different types of packets and the techniques that use them.) In general, the features of a packet depend on several considerations. Each protocol, as it's developed over time, makes certain assumptions about whether bandwidth is available, or whether there's too much noise and therefore too much retransmission needed, or whether the key issue is latency. Packets of different sizes may therefore perform differently in different environments