Messaging pattern

In software architecture, a messaging pattern is a network-oriented architectural pattern which describes how two different parts of a message passing system connect and communicate with each other.
UDP
In telecommunications, a message exchange pattern (MEP) describes the pattern of messages required by a communications protocol to establish or use a communication channel. There are two major message exchange patterns — a "request–response" pattern, and a "one-way" pattern. For example, HTTP is a "request–response" pattern protocol, and UDP is a "one-way" pattern.
SOAP.
The term "Message Exchange Pattern" has a specific meaning within the Simple Object Access protocol (SOAP). SOAP MEP types include:
ØMQ.
The ØMQ message queueing library provides so-called "sockets" (a kind of generalization over the traditional IP and Unix sockets) which require indicating a messaging pattern to be used, and are optimized for each pattern. The basic ØMQ patterns are:
Each pattern defines a particular network topology. Request-reply defines so-called "service bus", publish-subscribe defines "data distribution tree", push-pull defines "parallelised pipeline". All the patterns are deliberately designed in such a way as to be infinitely scalable and thus usable on Internet scale.