Telos Zephyr Xstream - Manual (Page 345)

USER’S MANUAL
Appendix 8 – Ordering ISDN for the USA and Canada 333
Details, Details
In order to communicate accurately what it is you need, we think you should be familiar with
the vocabulary used to describe ISDN. As with anything, for best results, it helps to know what
you are talking about. For an in‐depth glossary of terminology please check Appendix 10
(Glossary) or Telos’ web site at
http://www.telos‐systems.com .
Protocols
In a perfect world, all ISDN terminal equipment would work with all ISDN lines, without regard
for such arcana as 5ESS, DMS100, CSV/CSD, SPIDs, etc. The USA ISDN “standard” had been
evolving for several years. The good news is that it has now settled down, with most new
installations using National ISDN‐1 or National ISDN‐2 (see below).
At their central offices, the telephone companies use AT&T/LUCENT 5ESS, Northern Telecom
DMS100, or Siemens EWSD switching equipment. While each will work with the Zephyr
Xstream, there are some differences, which need to be taken into account when lines are
ordered and used. Each has 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.
There are standard protocols that all switches may provide, called National ISDN‐1 (NI‐1) and
National ISDN‐2 (NI‐2). These protocols were standardized and specified by Bellcore, the
technical lab jointly owned by the phone companies. However, both AT&T and Northern
Telecom had versions of ISDN which predated the NI‐1 standard and a few switches may not
been upgraded to the new format. In that case you would need to use one of the older
"custom" protocols.
There is also a newer NI‐2 standard, but it is designed to be compatible with NI‐1 for all of the
basic functions and therefore is acceptable to device such as the Zephyr that use NI‐1.
SPIDs
Service Profile Identification (SPID) numbers are required in all but one of the AT&T protocols.
These numbers are given to the user by the phone company and must be entered correctly into
the Zephyr Xstream in order for the connection to function. SPIDs usually consist of the phone
number plus a few prefix or suffix digits (it may or may not include the area code). There is
frequent confusion between phone numbers and SPIDs, even among Telco personnel. While
the SPID frequently includes the corresponding phone number, this is not necessarily the case.
The intention of the SPID is to allow the Telco equipment to automatically adapt to various user
requirements, by sensing different SPIDs from each type or configuration of user terminal.
None of this matters with our application, but we must enter the SPIDs nevertheless. BellSouth
has proposed, and most of the other telephone companies have agreed to implement, a
standardized SPID for new installations. This has been implemented by most Telcos. The
standard is area code+phone number+0101 (XXXYYYZZZZ0101). See Appendix 4 for a list of SPID
formats used by the Telcos prior to the standard.
Unless you are using the AT&T PTP protocol, your Telco service representative should give you
one SPID for each B channel you order. Don’t let the phone company installer leave without