Multipoint Applications; Leased Backup Applications; Comsphere 391X Series Models - Paradyne COMSPHERE 3910 Installation And Operation Manual

COMSPHERE 3900 Series Modems

Multipoint Applications

In multipoint applications, leased-line circuits are used for time sharing the same front-end
processor (FEP) port with multiple remote locations. The FEP (via the control modem) regulates
traffic on the line by continuously polling the tributary DTE(s) in a predefined sequence. Only one
tributary can communicate with the control modem at a given time. Modems configured for Trellis
Multipoint (TMp) cannot be used in a point-to-point, constant carrier application. (Refer to the
Leased Line section in Chapter 4 for configuration options.)

Leased Backup Applications

In 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 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.

COMSPHERE 391x Series Models

The 391x Series family is available in two models: the Model 3910, a 4-wire/2-wire standalone
modem, and the Model 3911, a carrier-mounted version of the standalone unit. Both models offer a
variety of modulation schemes and network enhancements while still providing reliable,
high-speed data transmission using the latest in modem technology.
1-2
Mixed inbound rates for multipoint applications.
Convenient migration to new or optional features through software downloading.
Extended data circuits with diagnostics.
Network management system (NMS) support through the COMSPHERE 6800 or
6700 Series NMS using Advanced Diagnostic protocol (ADp).
Complement of self-tests, local and remote loopbacks.
CCITT V.42bis and MNP Class 5 data compression.
Virtual error free data integrity with CCITT V.42 and MNP Level 4 error control.
Dial access security.
Automatic and manual backup with standby capabilities for 4-wire/2-wire leased-line
applications. (The backup facility may be either a 2-wire dial line or a 2-wire leased line.)
November 1996 3910-A2-GN32-30