Desk ISDN phone MITEL 51004990 for ISDN lines, rated 2.5 A 250 V

ISDN desk phone MITEL 51004990 is designed for connection to ISDN telephone lines and provides reliable voice communication for office and home environments. The unit supports standard ISDN call handling and basic telephony functions suitable for everyday use where ISDN service is available. It is rated for operation with supply or line characteristics up to 2.5 A and 250 V and integrates with existing ISDN infrastructure to deliver clear voice transmission and straightforward line management.

Advantages

The device offers solid compatibility with ISDN networks and straightforward operation without the need for complex configuration. Its electrical rating of 2.5 A and 250 V ensures compatibility with common ISDN line conditions and contributes to stable performance. The handset and control layout are optimized for routine call handling, reducing the learning curve for users familiar with standard desk phones. The build and connectors follow conventional ISDN telephony standards, enabling quick integration into PBX or direct line setups.

Suitable for

• Office workstations requiring standard ISDN voice calls
• Home offices with active ISDN service
• Small businesses using ISDN telephone systems or PBX integration
• Environments needing a basic, reliable desk phone for voice-only communication

Key specifications

• Connection type: ISDN line compatibility for standard voice calls
• Electrical rating: 2.5 A, 250 V for line/supply conditions
• Form factor: desk/desktop phone with handset and base unit
• Primary function: voice telephony with standard ISDN call handling
• Intended environment: office and home use with ISDN service

How to use

Connect the phone to the ISDN line following the installation instructions provided with the telephone system or from the network operator. Ensure line power and ISDN service are active and that connections are made to the appropriate ISDN ports. Use the handset and keypad to place and receive calls; basic call features such as answer, hang up, and numeric dialing operate as on standard desk phones. If integrating with a PBX, configure the PBX to recognize the device as an ISDN endpoint according to the PBX documentation.

Usage recommendations

Use this MITEL ISDN desk phone in locations where ISDN service is maintained and line characteristics do not exceed the specified 2.5 A, 250 V rating. For installation and troubleshooting, consult your network operator or PBX administrator to ensure proper line termination and compatibility. Avoid exposing the unit to moisture, extreme temperatures, or electrical spikes beyond specified limits.