Defining a transmission queue

A transmission queue is a local queue that is used when a queue manager forwards messages to a remote queue manager through a message channel.

The channel provides a one-way link to the remote queue manager. Messages are queued at the transmission queue until the channel can accept them. When you define a channel, you must specify a transmission queue name at the sending end of the message channel.

The MQSC command attribute USAGE defines whether a queue is a transmission queue or a normal queue.

Default transmission queues

When a queue manager sends messages to a remote queue manager, it identifies the transmission queue using the following sequence:

  1. The transmission queue named on the XMITQ attribute of the local definition of a remote queue.
  2. A transmission queue with the same name as the target queue manager. (This value is the default value on XMITQ of the local definition of a remote queue.)
  3. The transmission queue named on the DEFXMITQ attribute of the local queue manager.
For example, the following MQSC command creates a default transmission queue on source.queue.manager for messages going to target.queue.manager: 

DEFINE QLOCAL ('target.queue.manager') +
DESCR ('Default transmission queue for target qm') +
USAGE (XMITQ)

Applications can put messages directly on a transmission queue, or indirectly through a remote queue definition. See also Creating a local definition of a remote queue.