Card Options - ADTRAN Express 5200 User Manual

Chapter 1. Introduction
both the physical integrity and the signaling state are restored, the
unit drops the dial backup call and reverts to the main line.
For frame relay dial backup, either Express 5200 can originate a dial back-
up connection. The answer/originate option has no effect in frame relay
mode.
Only point-to-point frame relay is supported with the Express 5200. The
Express 5200 only supports one network connection at a time. Therefore,
when a dial backup connection is made, the main network port is discon-
nected from the data path. This isolates any other nodes on a frame relay
network if a dial backup connection is established with a single node.
The Express 5200's unique DBU cards are field-installable by the
customer. See the section DBU and Voice Interface Card Slots on page
2-4 for information on installing DBU cards. The four backup
options are described in the following sections. Contact the local
telco provider to determine which services are available in your
area.

Card Options

4-Wire Switched 56 DBU Card
This dial-up 4-wire SW56 card allows you to pay for data
connection only for the time the unit is active. The regional
operating companies provide the 4-wire local loop service to SW56
customers.
V.34 DBU Card
This module backs up the leased line application at data rates up to
33.6 kbps over an ordinary telephone network.
ISDN DBU Card
1B+D Basic Rate ISDN service provides a switched 56/64 kbps
circuit.
DCE Card
This module connects an external DCE device to the Express 5200
for the purpose of using an external DSU/CSU to support access
rates up to 512 kbps. The DCE card is inserted into the DBU card
slot, but it is not used for dial backup.
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