When Module for AS4 plays the role of initiating MSH, the pull transfer is initiated by the wm.ip.estd.as4.msh:sendPull service. The module uses the mpc and pmodeId input parameters that are passed to this service to fetch the appropriate TPA and identify the messaging parameters for the transfer.

The parameters specified in the requestSM leg of the TPA are used to generate the pull signal and identify the address of the responding MSH. When the user message is received as a response to the pull signal, the module uses the requestUM leg of the TPA to process the user message.

For more information about configuring the module to use the One-Way/Pull MEP, see Configuring Trading Partner Agreements. For more information about the sendPull service, see Built-In Services.