Adobe Access client 3.0 and higher send a Get Server Version request in order to determine the capabilities of the server. All servers using Adobe Access SDK 3.0 and higher must implement support for Get Server Version requests.
com.adobe.flashaccess.sdk.protocol.getversion.GetServerVersionHandler
com.adobe.flashaccess.sdk.protocol.getversion.GetServerVersionRequestMessage
For Adobe Access SDK 4.0 and higher, the response to a Get Server Version request indicates to clients that the server supports versions 3 and 4 of the Adobe Access protocol.