2.2.1.4 ASF Data Packet Payload
Each RTP payload format header is followed by a payload that contains an ASF data packet. The ASF data packet can be partial if it has been fragmented across multiple RTP payloads.
If the ASF data packet contains a Padding Data field, as specified in [ASF] section 5.2.4, that field SHOULD be removed before encapsulating the ASF data packet in an RTP packet. If the Padding Data field is removed, the Padding Length field in the ASF payload parsing information section (as specified in [ASF] section 5.2.2) MUST be updated to indicate a nonexistent Padding Data field.