2154595 - Message could not be forwarded to the JCA adapter: Connection refused/reset/timeout

You are sending/receiving messages using SAP AS2 adapter, and the following errors occur during the processing:

• Message could not be forwarded to the JCA adapter. Reason: Message cannot be delivered: java.net.ConnectException: Connection refused: connect
  
  
• MP: exception caught with cause javax.resource.ResourceException:Message cannot be delivered: java.net.ConnectException: Connection refused: connect
  
  
• Exception caught by adapter framework: Message cannot be delivered: java.net.ConnectException: Connection refused: connect Delivery of the message to the application using connection AS2_http://sap.com/xi/XI/AS2 failed, due to: com.sap.engine.interfaces.messaging.api.exception.MessagingException:
  javax.resource.ResourceException: Message cannot be delivered:java.net.ConnectException: Connection refused: connect
  
  
• Message status set to NDLV 
  
  

Or the following errors:

• Connection reset
• Connection timeout

• PI Release Independent
• SAP NetWeaver
• SAP Process Integration

Connection reset; Connection refused;Connection timeout; AS2 adapter, duplicate, HTTP 200, Process Integration 7.30, PI 7.30, Process Integration 7.31, PI 7.31, Process Orchestration 7.40, PI 7.40, PO 7.40, Process Orchestration 7.50, PI 7.50, PO 7.50, NetWeaver, XI , KBA , BC-XI-CON-B2B-AS2 , Applicability Statement Protocol Adapter , Problem