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Telephone-Line Manager, 2-Line, 8-Port Base Unit


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


  • Require only one security device on each telco line to secure the entire group.
  • No programming needed. Easy to upgrade.
  • T-configuration adds flexibility and versatility—subscribers can use outbound and inbound ports.

  • Face it—you need high-speed modems to conduct business. But if your budget doesn’t include installing a dedicated line for each of your users’ desktop modems, the Telephone Line Manager is the answer.

    BLACK BOX® Telephone Line Managers enable multiple users to connect to the telco lines already installed in your building. Each unit is completely automatic and prevents modems and other connected analog communications devices from interrupting established connections when bidding for a line.

    The line managers are perfect for small- to medium-sized businesses with one to four lines. In applications where only a single line is used, you can connect the line managers to a workgroup via an existing RJ-11 fax-line jack.

    For systems using two or four lines, simply install a line manager in your wiring closet along with the rest of the telco equipment. As the number of users increases, you can expand the number of subscriber ports easily—just daisychain 2- and 4-line units or add expansion modules to the 4-line base unit.

    Both 1-line models (40423–40424) are nonpowered switches. They derive their power from the telco lines and can operate as standalone units for workgroups. Our 2- and 4-line models (40425–40426) are switches powered by a 9-volt wallmount transformer. You can daisychain the master units together or use them to support a base unit running from each subscriber port.

    The S-Configuration Expansion Module (40427) for model 40425 and the S-Configuration Expansion Module (40428) for model 40426 provide eight additional subscriber ports for outbound calls. You can stack up to seven of these expansion modules to provide Internet access for up to 64 subscribers from just one 2- or 4-line unit!

    The T-Configuration Expansion Module (40429)for model 40426 provides two additional telco line ports as well as eight extra subscriber ports. This configuration adds additional versatility—16 subscribers have access to two high-priority primary lines and two shared alternate lines only for outbound calls; inbound calls are routed to the first two subscriber ports.

    Tech Specs

    Connectors Line Side: 40423–40424: (1) RJ-11; 40425: (2) RJ-11; 40426: (4) RJ-11;
    Indicators LEDs: (1) Power/reverse polarity status indicator per connected telco line
    Interface PSTN
    Line Type 2-wire dialup
    Power 40423–40424: From the telco line; 40425–40426: 9-V wallmount transformer
    Size 40423–40424: 1"H x 3.8"W x 2.3"D (2.5 x 9.7 x 5.8 cm); 40425–40426: 0.8"H x 7.5&"W x 4.3"D (2 x 19.1 x 10.9 cm)
    Subscriber Side 40423: (4) RJ-11; 40424–40426: (8) RJ-11
    Weight 40423–40424: 0.3 lb. (0.1 kg); 40425–40426: 2.5 lb. (1.1 kg)

    * 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 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 Telephone-Line Manager, 2-Line, 8-Port 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.