Several BRI switch options are available for configuring your router. These switch types vary
according to geographic location. The available switch types are listed in Table 26.2.
TABLE 2 6 . 2
ISDN BRI Switch Types
Switch Type Typically Used
BASIC-1TR6 1TR6 switch type for Germany
BASIC-5ESS AT&T 5ESS switch type for the U.S.
BASIC-DMS100 Northern DMS-100 switch type for the U.S.
BASIC-NET3 NET3 switch type for the U.K. and most of Europe
BASIC-NI National ISDN switch type for the U.S.
BASIC-TS013 TS013 switch type for Australia
NTT NTT switch type for Japan
VN3 VN3 and VN4 switch types for France
EZ-ISDN North American ISDN standard service package
A benefit to using a BRI is being able to make a voice call while maintaining your Internet
connection. This is a great solution for SOHO deployments.
The D channel can also be used to transport packet-switched data communications
such as X.25. In fact, Cisco has enabled this feature in version 12 of its IOS
software. The feature is called Always On/Dynamic ISDN (AO/DI). Basically, it
enables the low-bandwidth traffic to use the D channel and initiates a call by
using one or two B channels if the traffic warrants. This feature will be most useful
for point-of-sale applications but is not supported by all service providers.