Raymar 326X V.32bis Series, Руководство пользователя

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0049-1800-xxx 326X V.34, V.34-SDC and V.32bis Series Modem – USER’S GUIDE 02/23/2010
Rev. A
Page 68 of 205
SDC Option Set 4 – Sync Leased Line with Dial Restoral; No ACU
(Models 3261/63/66/68)
Point-to-Point Leased Line Application with Dial Restoral
Figure 4-5 shows a typical point-to-point leased line application, with SDC modems providing
leased line and dial back-up for a bridge/router network. A Raymar-Telenetics Network
Management System (NMS) is shown. This application could apply to any nodal equipment
connections (e.g. bridges, routers, or X.25 PADs).
With the modem’s integral restoral capabilities, if leased circuit operation is disrupted, the modems
restore the connection over a single dial line through the PSTN.
The modem uses the adaptive rate feature in the V.34 Auto modulation mode. This ensures
maximum throughput when line quality deteriorates. If restoral criteria are met, the modem
automatically reroutes data traffic through the PSTN. At that time, the modem attempts to run at its
maximum rate over the dial line, and falls back to lower speeds if required. After an hour, the
modem returns to the leased line.
Select SDC Option Set 4
for this application.
Note the following:
•
The line configuration default of Option Set 4 is Two-Wire Leased Line.
•
With Option Set 4, the modem provides the network timing (
Clock
=Internal).
•
To specify a non-default rate at which the modem communicates with the DTE, use the
DTE
Rate
(AT
*
DE). See the DTE Rate description in Appendix A.
•
Select SDC Option Set 4 in both the local and remote modems, and ensure that
Mode
(AT
*
SM) is set the same in both modems.
•
If operating with the Raymar-Telenetics or Motorola 6500
PLUS
that has the Link Back-Up
option, set
DTR
=108.2 (the default is 108.1 for 6500s without the Link Back-Up option).