Black Box 1-800-316-7107

Helping you is our priority at Black Box.

We're committed to providing the best customer service in the industry. We're here for you, 24/7, 365.

We'll call you

A technical expert will call you shortly.

Submit Connecting call...

Call Us

Customer Sales & Service Support

Black Box Brand Product Support

IT Services & Voice Support

Send us a FAX


T1/FT1 CSU/DSU, V.35

Process high-speed T1 data—and even share bandwidth—with one of these CSU/DSUs.


Please call 877-877-2269 for a replacement product or part.
Extended Double Diamond™ Warranty Available (3 Additional Year)

Product Features

  • High reliability.
  • Comply with full and fractional T1, and they support Frame Relay services.


  • Has a V.35 female connector for the data port.
  • Also has a DB9 (DCE) console port, which enables a connection for local and remote maintenance.
  • Includes (1) 6-foot (1.8-m) RJ-48C cable.

  • ThisCSU/DSU is perfect for router-to-router and LAN-to-WAN enterprise links, as well as for image transfers, videoconferencing, and host-to-host communications.

    Tech Specs

    Clocking Network interface or internal oscillator
    Connectors (1) M/34 F, (1) RJ-48C, (1) DB9 F (DCE), (1) barrel plug
    Data Rate 64 kbps to 1.544 Mbps
    Dimensions 2"H x 8.5"W x 5.5"D (5 x 21.5 x 14 cm)
    Interface V.35 F
    Line Encoding AMI/B8ZS and framing D4 or ESF
    Line Type T1
    MTBF 72.053 hours
    Operation Full-duplex
    Protocol Synchronous
    Weight 3 lb. (1.4 kg)

    NOTE: For rackmount and DC versions, contact our FREE Tech Support.

    This product works with:
  • V.35 Interface Cable, Male/Female (EYN450T-MF)
  • DB9 Extension Cable (with EMI/RFI Hoods) (EDN12H)
  • RS-530 Data Cable, Male/Female (EVNT530-MF, EVN530-MF)
  • 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.



    Double Diamond Warranty

    Extended 1 Year Warranty Available

    Protect your purchase with an additional 1 Year Double Diamond™ warranty!
    Cost: $78.80

    Extended 3 Year Warranty Available

    Protect your purchase with an additional 3 Year Double Diamond™ warranty!
    Cost: $157.59


    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 T1/FT1 CSU/DSU, V.35 comes with a standard 1 Year Double Diamond™ Warranty (Standard) 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.