Hughes DiRECWAY DW7700, Дополнительное руководство пользователя

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Chapter 2 • DW7700 component and feature descriptions
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1036332-0001 Revision C
If the satellite link between the DW7700 and DIRECWAY NOC
fails or degrades below a certain threshold, the DW7700
automatically switches to DVADB mode. The DW7700’s
internal modem establishes a connection to a national network of
dial access numbers, which are known as a Points of Presence
(POP). Each POP acts as a Virtual Private Network (VPN) entry
point into your network or the Internet. Packets are sent from the
DW7700 through the POP to the DIRECWAY NOC, which
forwards the packets to the destination server. If necessary,
packets are routed from the destination server to the DIRECWAY
NOC and back to the DW7700
DVADB introduces no additional load on the DW7700 and does
not affect any existing DW7700 features, but it does cause the
DW7700 to send and receive data at a slower rate.
Optional protection module
In some countries, the telephone lines are configured such that a
protection module is required between the DW7700 and the
outside PSTN telephone line. In those cases, Hughes provides
such a module (Part #9012740-0001). This module is a high
speed electronic circuit protector that provides over-voltage and
over-current protection in one component.
As of the date of this manual, the following countries require the
use of this optional protection module;
•
Brazil
The protection module includes a short telephone cable that
connects to the telephone line port on the DW7700 and a
grounding cable with a ring terminal that connects to the
DW7700’s backplane.
Figure 3 illustrates DW7700 DVADB connections with the
optional protection module. Figure 4 illustrates details of the
protection module connections.