Isdn For Resilience; Isdn Top-Up Bandwidth-On-Demand; Figure - Bay Networks NauticaRS Reference Manual

ISDN for Resilience

ISDN Top-Up Bandwidth-On-Demand

117237-E Rev.00
ISDN means that your organization no longer needs to lease 64
Kb/s or lower-speed lines to interconnect LANs. The Nautica
series can take advantage of widespread ISDN availability by
providing several Basic Rate Interfaces (BRI) or a Primary Rate
Interface PRI), providing up to 30 "B" channels in Europe or 23
"B" channels in North America. ISDN links can be used to
replace leased lines (as backup if a leased line fails) or in addition
to leased lines (for extra bandwidth as needed).
Using ISDN is the most cost-effective and responsive means of
providing resilience to line failure. The Nautica Series can be
configured to respond to line failures by connecting to one or
more ISDN channels. Service is usually restored within three to
seven seconds, which ensures that users are not interrupted.
The Multilink facility allows data to be shared evenly across all
available links (leased and ISDN), and also allows multiple ISDN
channels to back up a higher-speed leased line. If configurable
load thresholds on any link are exceeded, the Nautica Series
router can be configured to dial up additional bandwidth using
64 Kb/s ISDN channels between router pairs. This increases the
flexibility of network configurations, allowing peak demand to be
covered only when it occurs.
ISDN means that system administrators can size their networks
accurately without worrying about peak demand operation. The
Nautica router automatically sets up one or more ISDN circuits to
provide extra bandwidth when the leased line or single-channel
ISDN line utilization exceeds configurable thresholds. Data is
then shared across all available links, allowing the ISDN calls to
be cleared automatically when demand decreases and so
minimizing costs.
Introduction to Protocols and Routing
1-5