X

X.25

The CCITT standard used for communication over a packet-switching network. X.25 uses the QLLC (qualified logical link control) protocol.

XID

Exchange Identification. An identifier that is exchanged between nodes on an SNA network, and that allows the nodes to recognize each other and to establish link and node characteristics for communicating. With SNA Server, two kinds of XIDs can be exchanged: Format 0 XIDs (containing only basic information) and Format 3 XIDs (containing more detailed information). See also Format 0 XID and Format 3 XID.