X.25 packet switch services 1

[Riiaz]

What really is X.25 protocol and what advantages are in it?

 

[MBH]

I'm not a historian, but:<br>
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X.25 was one of the first international Protocals used by National Telephone companies, for both Domestic and International exchange of data. Based on the agreement of the members of the CCITT, it incorproated a packet based system, error correction, and definitions for layer 1 to 3 of the OSI 7 layers. Note: This was pre-OSI.<br>
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In the U.S. we started ARPANET, that was also packet based, but was not agreed to by the CCITT, if you look at the frame structure, you will quickly see many similarities of both packet formats.<br>
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At the macro level, the primary advantage of X.25, was its universal acceptance. This allowed the flow of commercial systems over international transmission systems. As recent as the 1990, countries have been installing X.25 networks so customers can connect anywhere in the world.<br>
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The internet is quickly becoming the replacement for this standard, with IP packets, becoming Globally available.<br>
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Couple of thoughts any way.<br>