Integrated Services Digital Network (ISDN)
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North America, where the NT1 function isn't provided by the carrier
network.)
ISDN Protocols
ISDN protocols are defined by the ITU, and there are several series of pro-
tocols dealing with diverse issues:
Protocols beginning with the letter E deal with using ISDN on the
existing telephone network.
Protocols beginning with the letter I deal with concepts, aspects, and
services.
Protocols beginning with the letter Q cover switching and signaling.
These are the protocols that we used to connect to an ISDN network
as well as troubleshoot.
ISDN Switch Types
We can credit AT&T and Nortel for the majority of the ISDN switches in
place today, but additional companies also make them.
In Table 10.1 under "Keyword," you'll find the right keyword to use
along with the isdn switch-type command to configure a router for the
variety of switches it's going to connect to. If you don't know which switch
your provider is using at their central office, simply call them to find out.
T A B L E 1 0 . 1
ISDN Switch Types
Switch Type
Keyword
AT&T basic rate switch
basic-5ess
Nortel DMS-100 basic rate switch
basic-dms100
National ISDN-1 switch
basic-ni
AT&T 4ESS (ISDN PRI only)
primary-4ess
AT&T 5ESS (ISDN PRI only)
primary-5ess
Nortel DMS-100 (ISDN PRI only)
primary-dms100
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