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CSU/DSU MS DBU Base Unit, Base Unit

Re-establish your data link fast—get failsafe DDS backup.


Please call 877-877-2269 for a replacement product or part.

Product Features

  • Supports DDS rates from 2.4 to 64 kbps, including 19.2 and 38.4 kbps.
  • Embedded SNMP and Telnet™ via dedicated RS-232 control port.
  • Two slots available.


  • The optional V.34 Modem Backup module (MOV3298426) gives you dial backup to re-establish your data links faster than ever.
  • The modular design enables you to upgrade to ISDN without replacing the entire unit.

  • Tech Specs

    Interface DTE: Both EIA-232 and V.35 electrical and physical DTE interfaces; Line: RJ-48S, 4-wire, full-duplex
    Power 115 VAC, 60 Hz, 7 W
    Size 2.4"H x 8"W x 10.4"D (6.1 x 20.3 x 26.4 cm)
    Speed Sync: 2.4, 4.8, 9.6, 19.2, 38.4, 56, and 64 kbps; Async: 2.4, 4.8, 9.6, 19.2, 38.4, and 57.6 kbps
    Weight 4.5 lb. (2.0 kg)
    This product works with:
  • CSUDSU MS DBU Backup Modules (MOV3298426 or MT139C)
  • RS-232 Cable, 25-Conductor, Male/Male (ECM25C)
  • V.35 Interface Cable, Male/Male (EYN450-MM)
    Questions? Contact our free Tech Support.

    * Technical specification weight is the unit weight. It is not the packaged shipping weight. For shipping weight, please contact Black Box customer service at 877-877-2269.

  • Warranty

    Double Diamond Warranty Diamond

    Double Diamond™ Warranty (Standard)

    Take the risk out of equipment purchases with the Double Diamond™ Warranty from Black Box Network Services.

    The Double Diamond Warranty is our warranty that protects your Black Box® brand products* from accidental damage, including drops, water, and power surges.

    The CSU/DSU MS DBU Base Unit, Base Unit comes with a standard None already included.

    During the warranty period, Black Box Network Services will repair or replace your damaged equipment within one week of receipt at NO CHARGE!*

    Plus, get an Extended Double Diamond Warranty.

    You can also extend your warranty or protect a previously purchased Black Box® brand product** for an additional year—for only 10% of the purchase price! Or, extend your coverage for a full three years for only 20% of the purchase price!

    Ordering an extended warranty is easy: When viewing a product in your shopping cart, just select the one or three years of additional coverage in the dropdown menu under “Warranty Options.” For details, contact Customer Service at 724-746-5500.

    * Warranty subject to certain exclusions and limitations ** Certain products may not be eligible.

    What’s more, we also have a 45-day return policy. Simply call Customer Service for a Return Authorization (RA) number, return your product in new condition and in the original package, and receive a full refund.