X.75

X.75 is an International Telecommunication Union (ITU) (formerly CCITT) standard specifying the interface for interconnecting two X.25 networks. X.75 is almost identical to X.25. The significant difference is that while X.25 specifies the interface between a subscriber (Data Terminal Equipment (DTE)) and the network (Data Circuit-terminating Equipment (DCE)), X.75 specifies the interface between two networks (Signalling Terminal Equipment (STE)), and refers to these two STE as STE-X and STE-Y. This gives rise to some subtle differences in the protocol compared with X.25. For example, X.25 only allows network-generated reset and clearing causes to be passed from the network (DCE) to the subscriber (DTE), and not the other way around since the subscriber is not a network. However, at the interconnection of two X.25 networks, either network might reset or clear an X.25 call, so X.75 allows network-generated reset and clearing causes to be passed in either direction.

Although outside the scope of both X.25 and X.75 which define external interfaces to an X.25 network, X.75 can also be found as the protocol operating between switching nodes inside some X.25 networks.

Further reading
  • Friend, George E.; John L. Fike; H. Charles Baker; John C. Bellamy (1988). Understanding Data Communications (2nd ed.). Indianapolis: Howard W. Sams & Company. ISBN 0-672-27270-9.CS1 maint: ref=harv (link)
  • Pooch, Udo W.; William H. Greene; Gary G. Moss (1983). Telecommunications and Networking. Boston: Little, Brown and Company. ISBN 0-316-71498-4.
gollark: If their system is only "secure" because you can't (aren't meant to) directly interact with it, it's *not secure*.
gollark: I'm not a fan of the "no modified clients" ToS thing, but I never found a particularly good reason to actually use one anyway.
gollark: So all we need to do is have PyroBot secretly log everyone's messages somewhere and then after a while use them for training, great!
gollark: Also, AI training needs powerful GPUs generally, I think, so it would cost a bit.
gollark: So you then get a bot which... says random things?
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.