Is x.224 specification freely available?

Question

I need to implement a simple probe that uses "open" microsoft rdp protocol. But that protocol refers to x.224 specification and ITU want money in order to download it. Is it any free version of x.224 protocol available?

Answer 1

While I was unable to find a free version of x.224 recommendation RFC1950 states this:

ITU-T Recommendation X.224, Annex D, "Checksum Algorithms,"
November, 1993, pp. 144, 145. (Available from gopher://info.itu.ch).
ITU-T X.244 is also the same as ISO 8073.

ISO 8073 is available on BANalyzer network protocol database.