ISDN Product Reviews

The Adtran ISU express is an ISDN TA with optional POTS jack and/or 14.4 Modem, it provides V.120 and sync-async PPP conversion.

Configuration is by AT commands and/or full-screen serial interface. The full screen interface is easy to use, and includes a status screen logging the most recent messages (including incoming and outgoing calls with phone number and results).

Extra phone features including 3-way calling, call waiting, and call transfer can all be used via the POTS interface. The Adtran can also be programmed with up to 10 numbers to accept calls from, and will reject all others. This model does not send Caller-ID information on the analog port.

• Documentation: Good. One hardware/software manual
• Protocols
  • ISDN: sync-async conversion
  • Modem: All speeds to 14.4Kbps
• Compression: Analog modem: MNP1-5
• Security:N/A
• Address limitations: N/A
• Usability
  • Configuration
    • User Interface: AT commands and full screen serial
  • Daily use: Simple
  • Subjective speed: No compression
  • Ability to force call: AT commands
  • Display: LED
• Reliability: Very reliable
• POTS: Realistic dialtone, 3-way, transfer, call-waiting features accessible, bad hangup detection
• I/O connections
  • ISDN: U interface in, no S interface out
  • Local:Serial
  • POTS:One

Adtran has a single page covering their entire ISU line.