3373052 - POLL_FAILED error when connecting CPI to third party systems using RabbitMQ Adapter (AMQP)

You're trying to pool messages from a third party system using the RabbitMQ adapter via Cloud Connector and CPI. However, you get the error: 

Error Details[CONTENT][CONTENT_DEPLOY][InstanceError] : {"message":"POLL_FAILED","parameters":["sap-it-rabbitmq://foo?acknowledgement=afterProcessing&concurrent=1&credential=[CREDENTIAL]&host=[HOST]&locationId=[LOCATION_ID]&port=[PORT]&prefetched=5&queue=[QUEUE]&senderAuthentication=[SENDER_AUTHENTIFICATION]&senderProxyType=OnPremise&tls=false&virtualHost=[VIRTUAL_HOST]"],"childMessageInstances":[{"message":"EXCEPTION","parameters":["com.sap.adapters.factory.saprabbitmq.exception.SapRabbitMQException: Connection is not established after 20Min for Connection URL: <url> "]}]}

• SAP Integration Suite 
• Cloud Integration

SAP Cloud Integration, SAP Integration Suite, CPI, Cloud Platform Integration, HCI, HANA Cloud Integration, AMQP, Queue, topic subscription, RabbitMQ, RabbitMQ Adapter, POLL FAILED, Pooling , KBA , LOD-HCI-PI-CON-SOAP , SOAP Adapter , Problem