2 Description
2-2
FrameSaver NP 64+ User’s Manual - Installation Guide
980-001-0221C
March
2001
ISDN Adapter
Option
The FrameSaver NP 64+ can be factory-optioned to include an integral ISDN Adapter
module.
The ISDN adapter provides Backup for the DDS line and/or additional Bandwidth On-
Demand. It also provides the integral Modem, B-Channel Dial-In/Dial-Out access (in
addition to POTS Line access).
ISDN Backup
Backup in Frame Relay Protocol utilizing the Router’s Primary Port can be via dedi-
cated PVCs on an alternate port, or the frame switch manager may reroute the original
PVCs to the Backup Frame Switch. It is also possible to bypass the entire Frame Relay
Network and initiate backup to a pool of ports on an alternate Frame Switch connected
directly to another Router.
A typical network configuration showing the backup connection to a Backup Frame
Switch using rerouted PVCs is shown in Figure 2-2.
Figure 2-2 Typical Backup Configuration
The backup process is described as follows:
•
FrameSaver NP 64+ detects loss of connectivity at DSU.
•
ISDN Adapter card calls Backup Frame Switch and is identified by caller ID.
•
Frame Switch Manager either reroutes original PVCs, or Frame Switch uses
alternate PVCs for the backup connection.
•
FrameSaver NP 64+ switches the data path when connected.
•
Associated routers determine that PVCs have been established through LMI
enquiries.
•
Communication is resumed.
D S U
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F ram eSaver N P 64+
U ser Location
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B ackup
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IS D N
PR
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B ackup N ode
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