are running at the same time. If a message receiver application is not running when a sender sends it a message, the queue manager will hold the message until the receiver asks for it. Ordering of all messages is preserved, by default this is in FIFO order of receipt at the local queue within priority of the message. Data transformation: e.g. Big Endian to Little Endian, or EBCDIC to ASCII. This is accomplished through the use of message data exits. Exits are compiled applications that run on the queue manager host, and are executed by the IBM MQ software at the time data transformation is needed. Message-driven architecture framework: IBM MQ allows receipt of messages to "trigger" other applications to run. Range of APIs: It implements the Java Message Service (JMS) standard API, and also has its own proprietary API, known as the Message Queuing Interface (MQI), which preceded the JMS several years in existence. As of version 8.0.0.4, MQ also supports the MQ Light API. Clustering: Multiple MQ implementations share the processing of messages, providing load balancing. Communication Queue managers communicate with the outside world either through: Bindings: a direct software connection. Generally faster, but limited to programs running on the same physical host as the queue manager. A network or "client" connection: applications using a client connection can connect to a queue manager on any other host in the network. The physical location of the queue manager is irrelevant, as long as it is reachable over the network. Communication between queue managers This relies on a channel. Each queue manager uses one or more channels to send and receive data to other queue managers. A channel is uni-directional; a second channel is required to return data. In a TCP/IP based network, a channel sends or receives data on a specific port. Channel types: Sending channel: has a defined destination and is associated with a specific transmission queue (the mechanism by which messages are queued awaiting transmission on the channel). Receiving channel: receives data from any other queue manager with a sending channel of the same name. When a receiving channel receives a message, it is examined to see which queue manager and queue it is destined for. In the event of a communications failure, MQ can automatically re-establish a connection when the problem is resolved. The listener is the application's network interface to the queue manager. The listener