Dual-Leased Backup Applications; Msd Application; Digital Bridge Application - Paradyne Comsphere 3920Plus Installation And Operation Manual

Dual-Leased Backup Applications

In dual-leased backup applications, a 2-wire leased line is used as the backup facility instead of the
normal 2-wire dial line. Plug the leased line into the jack labeled DIAL on the rear panel of the
modem (see Figure 2-1 in Chapter 2), and enable the Dual_Leased_Ln configuration option. (Refer
to the Leased Line — Mux Enabled or the Leased Line — Mux Disabled section in Chapter 4 for
configuration options.) Except for dialing, ring indication, and call progression functions, you
control the backup function as if it were a normal dial backup.

MSD Application

The Modem Sharing Device allows from 2 to 4 physical ports to share a communication channel.
When the Mux Mode option is set to TDM/MSD on a tributary, and at least one port has the MSD
mode setting enabled, then MSD is enabled. For more information, refer to the Mux Enabled
section of Chapter 4 for configuration options or the Point-to-Point MSD and Multipoint MSD
sample configurations in Appendix G.
When MSD mode is enabled:

Digital Bridge Application

The Digital (DTE) Bridge provides the ability for dial backup of a multipoint configuration by
bridging the signal on the digital side of the FEP end modems. In this configuration, only two ports
(both on the FEP side) are used on the control and backup modems. Data received on Port 1 is
transmitted across the communication link, as well as looped back out of Port 2. Data received
across the communication link and on Port 2 are sent out of Port 1. For more information, refer to
the Mux Enabled section of Chapter 4 or the Digital Bridging sample configuration in Appendix G
for sample configurations.
When the Digital Bridge is enabled, a new menu is present with the following conditions:
3920-A2-GN31-10
The MSD Control configuration option is added at the end of the Mux Sub-Group.
The EIA Port Sub-group includes the RTS Antistream configuration option.
TDM capability is disabled when DTE Bridge mode is enabled, therefore the rate of Port 1
is forced to run at the line rate.
Configuration options are provided for Port 1 only; Port 2 cannot be configured.
Ports 3 and 4 are not available.
Port-related tests, such as digital loopbacks and Pattern tests, are available for Port 1.
DTE Status, Health and Status, and LED control are available for both Ports 1 and 2.
April 1995
Introduction
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