The server MUST first follow the steps specified in section 22.214.171.124. Also, the server MUST verify that the LinkViewerToMacCancelReadBlock message adheres to the syntax specified in section 126.96.36.199.
If the server is currently sending Data packets that contain the ASF file header, it MUST discard any such Data packets that have not yet been sent.
The server MUST then wait for either a LinkViewerToMacCancelReadBlock message or a LinkViewerToMacCloseFile message or a LinkViewerToMacReadBlock message to be received from the client.
How to process a LinkViewerToMacCancelReadBlock message is specified in section 188.8.131.52. How to process a LinkViewerToMacCloseFile message is specified in section 184.108.40.206. LinkViewerToMacReadBlock message processing is specified in section 220.127.116.11.