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Router Feature Descriptions 93
ISDN
ISDN provides an inexpensive switched digital access to remote sites. The
ISDN BRI standard provides for:
•
Two high-speed 64Kbps bearer (B) channels used for voice or data
connections
•
One 16Kbps signaling data (D) channel used for call set-up, 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 Router supports one ISDN BRI line and either or both of the B-channels
for transferring data. Voice is transferred using either B-channel. If the two
B-channels are used for separate connections, each provides up to 64Kbps
transfer rates. Both channels can be used together to provide uncompressed
data transfer at up to 128Kbps. The router can also transfer compressible
data at up to 512Kbps.
A Network Terminator device (NT1) provides the interface between ISDN
terminal (router) equipment and the ISDN service provider. In North
America, the NT1 is provided by the customer; outside North America, the
NT1 is provided by the ISDN service provider. The Router comes with a
built-in NT1 (U interface).
Telephone Switch Support
The telephone switch types supported in North America include:
·
AT&T 5ESS custom
·
Northern Telecom DMS-100
·
Switches providing National ISDN 1 (NI-1) support
Outside of North America, the supported switch types are:
·
NET3 (European ISDN)
·
NET3SW (European Swiss-variant)