Switch User's Guide

About the CSX400
14 CSX400 and CSX400-DC User’s Guide
ISDN
ISDN provides an inexpensive switched digital access to remote sites. The ISDN BRI standard
provides for two high speed 64 Kbps bearer (B) channels used for voice or data connections and
one 16 Kbps signaling data (D) channel used for call setup, signaling and other information. ISDN
allows all types of information to be transmitted including voice, data, fax and video. Multiple
devices can be linked to a single ISDN connection, each having their own telephone number. Two
or more channels can be combined into a single larger transmission pipe offering variable
transmission speeds.
The CSX400 supports one ISDN BRI line and either or both of the B channels for transferring
data. If the two B channels are used for separate connections, each provides up to 64 Kbps transfer
rates. Both channels can be used together to provide uncompressed data transfer at up to 128 Kbps.
The CSX400 can also transfer compressed data at up to 512 Kbps.
A Network Terminator device (NT1) provides the interface between ISDN terminal (router)
equipment and the ISDN service provider. In the U.S., the NT1 is provided by the customer;
outside the U.S., the NT1 is provided by the ISDN service provider. The CSX400 supports the
WPIM-S/T by providing an S/T interface that requires an external NT1.
Telephone Switch Support
The following telephone switch types are supported within the U.S.:
• National ISDN 1 (NI-1)
• AT&T 5ESS with Custom Software
• DMS-100
Outside of the U.S. the following switch types are supported:
• NET3 (European ISDN)
• NET3SW (European Swiss-variant)
• NTT (Nippon Telegraph and Telephone)
• KDD (Kokusai Denshin Denwa Co., Ltd.)
• French Delta (VN4) switches