Specify the Message Partition Channel Value for the Outbound AS4 Message
You can specify the message partition channel (MPC) value with the Message Partition Channel element in the mapper for the outbound AS4 message.
MPCs allow for the partitioned transfer of AS4 messages between AS4 exchange participants. MPCs are used for both pushed and pulled messages. One MPC is used for a single message exchange between two participants. You use the Message Partition Channel element in the mapper to specify the MPC value on which the outbound AS4 message is set. That message is eventually pulled upon receiving the inbound pull request as per the AS4 specification.