Telos Zephyr Xstream User Manual page 152

Zephyr Xstream ISDN Compatibility
Protocols
The Telco network and the Zephyr Xstream communicate via a 'protocol' – the language the
user equipment and the telephone network use to converse (on the D channel) for setting up
calls and the like. This is where there are differences depending upon the central office
equipment used on the line and the standards which are supported by that particular
equipment. While each type will work with the Zephyr Xstream, the differences need to be
taken into account when lines are ordered and the Zephyr Xstream set up.
In the USA, telephone companies use either AT&T/Lucent 5ESS, Northern Telecom/Nortel DMS‐
100, or Siemens EWSD switches. Each of these can support the National ISDN 1 (NI‐1) protocol
standard, which has been specified by Bellcore, the technical lab that was jointly owned by the
phone companies. However, both AT&T and Northern Telecom had "custom" versions of ISDN
which pre‐date the NI‐1 standard and a few switches have not been upgraded to the newer NI‐1
standard.
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CURIOSITY NOTE!
There is also a newer National ISDN-2 (NI-2) standard, but it designed to be compatible with
NI-1 for all of the basic functions.
In Europe (as well as much of the rest of the world), the common standard is Euro‐ISDN,
following the ETS 300 standards. It is an (apparently successful!) attempt for all of the European
telephone networks to use a single, compatible protocol.
In Japan, the protocol used is called INS64.
USER'S MANUAL
Section 7: ISDN BASICS 140