X.75

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X.75 is an ITU standard that defines how two X.25 networks connect to each other. It is almost the same as X.25, but while X.25 defines the interface between a customer device (DTE) and the network (DCE), X.75 defines the interface between two networks (signaling terminal equipment, STE), called STE-X and STE-Y. This means that reset and clear signals can be passed in either direction between the networks at the inter-network link, whereas with X.25 those signals typically came only from the network to the subscriber. Note that, although outside the main scope of both standards, X.75 can also be used as the protocol between switching nodes inside some X.25 networks.