VSI X.25 for OpenVMS enables appropriately configured systems to connect to an X.25 Packet Switched Data Network (PSDN) via an X.25 Relay node on the same Local Area Network (LAN), via a DNA Phase IV X.25 connector node, or directly using a synchronous controller card for Alpha.

The product supports communication via PSDNs conforming to ITU/TSS recommendation X.25 1980, 1984, and 1988, or to international standard ISO 8208. Refer to the SUPPORTED PUBLIC NETWORKS section for the list of supported PSDNs. VSI X.25 V2.1 supports VSI OpenVMS for Integrity and VSI OpenVMS Alpha. VSI X.25 V2.1 for Alpha contains synchronous device drivers and is required when using synchronous communications options.

Note: VSI X.25 for OpenVMS I64 does not support synchronous device drivers and synchronous communications options.


VSI X.25 for OpenVMS software allows the system to:

Latest Version



Integrity: per active socket.
Alpha: Alpha-LP.