The syntax of this message is specified in section

A client's RunspacePool MUST be in an Opened or NegotiationSucceeded state (section while processing this message.

This message is received by a client from a server as part of a wxf:ReceiveResponse message (section targeted to a RunspacePool. A server sends this message to make a method call on a client host.

The client interprets the method and parameter information as described in section 2.2.6 and hands over the data to the higher-layer for its response. The client collects the response from the higher-layer, if any, and sends a RUNSPACEPOOL_HOST_RESPONSE message (section to the server.