Silence on the Wire

User Datagram Protocol

As defined in RFC768,^[77] UDP provides a minimal superset of IP functionality. UDP adds a mechanism for the local delivery of data, but keeps close to the level of unreliability of the underlying layer (as well as its low overhead). The use of UDP for communications can be likened to a phone service in which words sometimes get swapped or are dropped out of sentences, and there is no reliable caller ID—but the cost of a call is low, and your calls are answered quickly.

The UDP header (Figure 9-5) has a minimal set of features and is relatively simple. It introduces a small set of parameters that can be interpreted by the destination system and used to route a packet to a specific application or to verify that packet payload ...