Protocols/MSNP/MSN Protocol Version 9
MSNP9 was introduced with MSN Messenger 6.0. Most of the changes in MSNP9 exist solely to support Protocols/MSNP/MSNC1 (also known as P2P transfers). Connecting with the Messenger Service using MSNP9 is not much different from Protocols/MSNP/MSNP8
MSNP9 is no longer supported by the notification server (noted as of 2010), although MSNP8 is still supported.