Each chunk of data is included as the XML character data of the <data/> element after being encoded as Base64 as specified in Section 4 of &rfc4648;. Each block MUST be a valid base64 block with padding at the end if needed.
-The <data/> element MUST possess a 'seq' attribute; this is a 16-bit unsigned integer that acts as a counter for data chunks sent in a particular direction within this session. The 'seq' value starts at 0 (zero) for each sender and MUST be incremented for each packet sent by that entity. Thus, the second chunk sent has a 'seq' value of 1, the third chunk has a 'seq' value of 2, and so on. The counter loops at maximum, so that after value 65535 (215 - 1) the 'seq' MUST start again at 0.
+The <data/> element MUST possess a 'seq' attribute; this is a 16-bit unsigned integer that acts as a counter for data chunks sent in a particular direction within this session. The 'seq' value starts at 0 (zero) for each sender and MUST be incremented for each packet sent by that entity. Thus, the second chunk sent has a 'seq' value of 1, the third chunk has a 'seq' value of 2, and so on. The counter loops at maximum, so that after value 65535 (216 - 1) the 'seq' MUST start again at 0.
The <data/> element MUST also possess a 'sid' attribute that ties the data chunk to this particular IBB session.
In the case of IQ stanzas, if the packet can be processed then the recipient MUST reply with an IQ stanza of type "result".