The DynamicSurfaceFactory serves as an integration point for external content sources such as video pipelines and hosted external display protocols. A client configures the sideband content source using another protocol (for example, RDP) and assigns it a unique ID. The client then requests that the server access the content via DynamicSurfaceFactory by passing the same unique ID.
Note that since the IDs are passed across multiple protocols, the server can receive the requests in an arbitrary order. The server MUST properly handle the condition where it sees the DynamicSurfaceFactory request first and the content source is configured later, linking up the instances when both have arrived.