Datex

The most common usage today is for card payment terminals. Datex is an ideal medium for these, because of the short connection times and low data transfer rates they require. SMART is another popular application, though much less exposed to the public. For comparison, a typical payment terminal transaction is 800 bits in each direction.

The network guarantees an established connection in two seconds (in less than 100ms in 90 per cent of cases, less than 500ms in 99 per cent) and disestablishment in 200ms (less than 50ms in 90 per cent of cases). Available transfer speeds are 600, 2400, 4800 and 9600b/s for synchronous connections.

Additional services offered include direct selection (comparable in function to speed dial, optionally blocking other), blocking of incoming/outgoing calls (all or just international), queuing of incoming connections (useful for services), group numbers (clustering of nodes with a single access number), identification ("Caller ID"), closed groups (like a VPN, all the nodes can hail each other but are otherwise separated from the rest), connection redirection and transferred billing (recipient pays).

Billing includes a monthly subscription, a starting fee per connection and a fee per time unit while connected. They vary according to the transfer speed.

In Norway, the network was built and maintained by Televerket, a government owned company also in charge of the phone network. This institution was privatized in the form of Telenor, and the responsibility of Datex was handed over to them. In 1994, Telenor opened a new service, Dataframe, a Frame relay service, for business-to-business connections at greater transfer rates.

Datex is complemented by Datapak, a packet switched network.

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