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Invented in the mid 1970s, X.25 has become a worldwide standard for data communications in wide area networking. It provides a high quality communications capability between computers and has the capability to accommodate "noisy" and inaccurate data communications links through its error-detection and correction (retransmission) algorithms. X.25 receives information from your application and creates an X.25 packet by adding appropriate header and trailer information. Packets over a single link can accommodate a number of different sessions between different devices by putting each session's information on a different logical channel. The packet is then wrapped in an high level data link control(HDLC) frame for transmission across a link. X.25 accommodates switched and permanent sessions between devices and allows differing devices to negotiate on the specific options and features which will be used during the session. Established, reliable, stable. Worldwide support. What more could any WAN connection need? X.25 is supported by vendors and service providers throughout the world. Click here to see a representation of the X.25 protocol structure.

X.25 Protocol Structure

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