Black Box LRA005A-R2 - Manual (Page 15)

ASYNC ROUTER AR-P, AR-5, AND SYNC ROUTER USER’S MANUAL
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2.3 Async Router AR-5 (LRA005A-R2) Features
The Async Router AR-5 has five internal V.34 modems. It connects LANs and clients at up to 28.Kbps
over normal telephone lines.
2.4 Sync Router (LRS002A-R2) Features
The Sync Router works the same way as the Async Routers, except that it connects LANs over a variety
of synchronous serial line types:
• Leased digital data service at 56 Kbps (North America) or 64 Kbps (Europe), i.e., a fixed line from
one location to another, using an external Channel Service Unit/Data Service Unit (CSU/DSU).
• Switched 56 Kbps service, available in North America from either the local or the long-distance
telephone companies, using an external CSU/DSU with dialing capability.
• ISDN basic rate service at 56 Kbps (referred to as voice, or 56 Kbps data), 64 Kbps (referred to as
transparent data), or 128 Kbps (with bonding), using an external synchronous terminal adapter.
If you want to use ISDN circuits, we recommend using the ISDN models that will be released in
the future.
• Switched circuits, using synchronous V.34 modems (such as ZyXEL U1496+) over normal telephone
lines. This type of circuit is not generally useful, since the standard compressing asynchronous
modems used with the Router generally provide superior performance.
2.4.1 A UTOMATIC F ALLBACK
If a leased synchronous line fails, the Router’s built-in modem automatically supports fallback
to the modem, for both IP and IPX routing.
2.4.2 S YNCHRONOUS R OUTER I NTERFACE
The Sync Router operates as an interface between synchronous routers from:
• Cisco
• Novell (MPR = Multi-Protocol Router)
• XYPLEX
• Wellfleet
Supported CSU/DSUs include (but are not limited to):
For digital data service:
• Our CSU/DSU MS (part number MT132A-R2)
• LarsE M5600 Multi-rate CSU A CSU/DSU with dual interface mode (V.35/EIA-232).
• Motorola/UDS DSS/MR (the Router works with the V.35 version only, of this CSU/DSU).
• Motorola/UDS DSS/V.32 A CSU/DSU which can use a dial-up V.32 connection as backup
to a leased 56-Kbps line without using the modem port of the Router.
For switched-56 data service:
• Our CSU/DSU MS/DBU (SW56) (part number MT134A-R2): A CSU/DSU for 4-wire switched-56
service with AT-command or V.25 bis dialing support to RS-232 or V.35 DTE. This CSU/DSU can
also be used for digital data service (DDS).