What are senders and listeners in WebSphere MQ transport for SOAP?

Senders

A sender is called by the infrastructure (Axis or .NET) and writes a SOAP request for invocation of a service. In WebSphere MQ transport for SOAP the sender causes the request to be put to a WebSphere MQ request queue, setting up any specific expiry, persistence and priority options. Senders are fully described in Senders.

Listeners

A SOAP/WebSphere MQ listener process waits for incoming messages and then invokes the target Web Service through the Web Services infrastructure and waits for the response. The term listener is used here in its standard WebServices sense: these listeners listen on request queues for WebSphere MQ messages and are completely distinct from the standard WebSphere MQ listener invoked by the runmqlsr command. Listeners are fully described in Listeners.