USR Courier®56K* V.92 Business Modem - Discontinued

NOTE: The USR843453C has been discontinued. The Courier Lite 56K Business Modem (USR845686G-PRO) is the recommended replacement‡. The USR845686G-PRO does NOT support leased-line connections, Synchronous, or V.25 bis.

Overview & Features     Specifications    Feature spotlight     Data Sheet     Support

Mission critical dial-up connectivity for Business

USR3453C Product Diagram

The USRobotics Courier 56K Business Modem with V.Everything® and V.Everywhere® technology offers the perfect solution for both 'Out of Band Management' of networks or 'Point of Sale' applications. Many modems claim reliability, but few match the real-world performance of Courier modems. Even fewer offer the multitude of advanced business features found on this modem: global usage, Carrier Loss Redial, and Dial and Dialback Security. Remote management capabilities let you configure, set up, update or troubleshoot your modems from almost anywhere. Each Courier includes a VersaPower Kit - a 110V to 240V power supply that includes clip-on plugs for other regions, in addition a clip-on power cord adapter that can be used to make it an inline power supply is available in all Courier accessory kits. When failure is not an option, you need the world-class capabilities that only come from the top of the USRobotics product line.

Incredible Compatibility and Flexibility

  • V.Everything® Technology provides support for all key communications protocols
  • V.Everywhere® Technology so that one, highly reliable hardware platform supports connections with most international phone systems
  • Synchronous/Asynchronous, and leased-line support
  • Supports all major operating systems: DOS, Windows 3.1/95/98/Me/NT 4.0/2000/2003/2003 64 bit/XP/XP 64 bit/Vista/Vista 64 bit/Server 2008/Win 7/Win 7 64 bit/Win 8/Win 8 64 bit/Server 2011/Server 2012/Win 10/Win 10 64 bit/Server 2012 R2/Server 2016/Server 2019, UNIX, Linux – any operating system that supports an RS-232 serial port
  • VersaPower Kit (Universal power adapter) automatically handles global power variations from 100 V to 240 V and includes alternate plugs for use in other regions (N.A., Europe, the Middle East or Africa)

Integrated Multilayered Security

  • Dial security:
    • Autopass works with up to 79 users, and automates logging in between two Couriers by including the password in the V.42 error-control request
    • Password Prompting, works with any type of modem, where the host Courier requests a password from those dialing in
  • Dialback security checks incoming calls for password authorization and then dials back predefined numbers to assure only appropriate users establish connections

Rock-solid Reliability

  • Carrier Loss Redial automatically senses, redials, and re-establishes dropped remote connections – creates a virtual leased-line connection between two modems, over regular dial-up lines
  • Advanced Line Probing technology finds the fastest connection and maintains connections under poor line conditions
  • Brown-out Protection assures you stay connected even in areas with poor power facilities
  • Robust, business-oriented design, component selection, testing, and experience to support non-stop operation

Powerful Management Tools

  • Remote Management lets you configure or troubleshoot from almost anywhere
  • Instant Update automatically checks the USRobotics web site for code updates when you're online and downloads new features at your convenience
  • Remote Flash capability lets you upgrade Courier modems at remote locations from a central site

** Support for 64 bit operating systems requires a driver update (available in the support section of this website).
* Capable of receiving at up to 56 Kbps and sending at up to 48 Kbps (or 31.2 Kbps with V.90 server). Due to FCC regulations on power output, receiving speeds are limited to 53.3 Kbps. Actual speeds may vary. V.92 and V.90 features require compatible phone service and support from your Internet Service Provider (ISP). USRobotics modems featuring V.92 enhancements are backward compatible and will negotiate the highest possible speed when connecting to an ISP.
† Requires Windows operating system.

‡ Courier Lite (USR845686G-PRO) is the recommended replacement for Courier USR843453C, but features and specifications do vary. It is suggested to verify requirements before purchasing replacement units.


Courier®56K* V.92 Business Modem


Recommended Replacement‡: USR845686G

Product Code : USR843453C

Approved for EU , Israel, South Africa, Pakistan

Additional Availability

US & Canada - Discontinued

Global Country Approvals & Accessory Kit Guide
Approved for use in over 75 countries*!

Additional Power Supply

110-240 V for US, UK and Europe
3453C Power Supply

* Kit may be required.

Contact Us

  • Phone (UK):
    +44 (0)808 234 5935

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