Data fields that support adapting to a constantly changing data provider topology?

Hi Folks,

Scenario: You have an application that receives data from a set of data providers. The application operates over a long period of time. The set of data providers is constantly changing. You are designing a data model for use by the application and data providers. A design goal of your data model is to support the constantly changing data provider topology. 

Question: What data field(s) would you put into your data model to support your application in adapting to a constantly changing data provider topology?

/Roger