How to support callbacks from ERP – does SOA need to enable anything for external listeners?

Summary: We are looking to implement a callback mechanism from our ERP system into our integration layer. The use case involves the ERP triggering an outbound callback (e.g. after a business process completes) that needs to be received by an external listener or service.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):