Yealink T42S IP Phone, 12 Lines. 2.7-Inch Graphical Display. Dual-Port Gigabit Ethernet, 802.3af PoE, Power Adapter Not Included

Yealink T42S IP Phone – 12-Line Business Deskphone

The Yealink T42S is a feature‑rich, dual‑port Gigabit Ethernet IP phone designed for modern business environments that demand reliable voice quality, robust connectivity and flexible configuration. With its compact form factor, intuitive interface and extensive protocol support, the T42S delivers an exceptional communication experience for small to medium‑sized enterprises.

Key Design & Build

• Dimensions: 212 mm (width) × 175 mm (height) × 189 mm (depth)
• Weight: 1.2 kg – lightweight enough for desk or wall mounting
• Color: Sleek black finish that blends seamlessly with any office décor
• Mounting Options: Supports both desk and wall installation, providing flexibility in workspace layout
• Display: 2.7‑inch TFT LCD (192 × 64 pixels) with backlight, offering clear visibility of caller ID, status indicators and menu navigation
• Buttons: Six programmable keys for quick access to frequently used functions or extensions
• Headset Compatibility: Wired headset support via the standard RJ‑9 connector (2 ports)
• Power Options: Dual‑port Gigabit Ethernet with IEEE 802.3af PoE support; power adapter not included, allowing seamless integration into existing PoE networks

Connectivity & Network Features

• Ethernet Ports: Two 10/100/1000 Mbps RJ‑45 ports for high‑speed data and voice traffic
• PoE Standard: IEEE 802.3af – delivers up to 15.4 W of power over the network cable, simplifying deployment
• USB Port: One USB 2.0 port for firmware updates or peripheral connectivity (e.g., external storage)
• Supported Protocols: SIP v1 & v2, LLDP/CDP/DHCP, OpenVPN, IEEE 802.1X, IPv6, FTP/TFTP/HTTP/HTTPS – ensuring compatibility with a wide range of VoIP infrastructures
• Quality of Service (QoS): Built‑in QoS support prioritizes voice packets for crystal‑clear audio even on congested networks
• Full Duplex: Enables simultaneous transmission and reception, eliminating echo and improving call quality

Voice & Audio Capabilities

• Codecs Supported: G.711 (μ/α), G.722, G.723.1, G.726, G.729ab, Opus, iLBC, CNG, VAD – providing flexibility for bandwidth optimization and high‑definition voice
• HD Voice Quality: Clear, natural sound with minimal latency; ideal for conference calls and multi‑party sessions
• Digital Volume Control: Precise adjustment of speaker volume without distortion
• Integrated Speakerphone: Hands‑free operation with built‑in microphone and speaker, supporting up to 12 simultaneous lines
• No Bluetooth or Wi‑Fi: Focused on wired reliability; wireless connectivity can be added via external adapters if needed

Call Management & Features

• Lines: Supports up to 12 VoIP accounts, allowing multiple extensions or SIP trunks on a single device
• Caller ID & Call Waiting: Displays caller information and notifies of incoming calls while engaged in another conversation
• Call Transfer & Forwarding: Full support for both attended and blind transfer, as well as call forwarding to other numbers or extensions
• Conference Calling: Enables multi‑party conferences with up to 12 participants; includes mute, hold and speakerphone controls
• Voicemail Integration: Built‑in voicemail access with playback, deletion and notification features
• No Caller ID Blocking or Call Screening: Provides straightforward call handling without advanced filtering options
• Call Recording & Transfer: Supports recording of calls for compliance or training purposes; can transfer recordings to external storage via USB
• Auto‑Answer & Call Waiting: Automatically answers incoming calls and alerts the user when another call arrives
• Redial, Rejection of Anonymous Calls, and Call Retention: Enhances user convenience and security by allowing quick redials, blocking unwanted callers and retaining missed calls for later review

Address Book & Contact Management

• Capacity: Stores up to 1,000 contacts in the local address book
• Import/Export: Supports CSV or vCard formats via USB for easy migration of contact lists
• Search & Quick Dial: Fast lookup and quick dialing from the phone’s interface
• Call History: Records recent calls, including timestamps and durations, facilitating call tracking and reporting

Power & Energy Efficiency

• PoE Power Input: Up to 15.4 W via IEEE 802.3af; eliminates the need for separate power supplies
• Energy‑Saving Mode: Automatically enters low‑power state during inactivity, reducing overall energy consumption
• Operating Temperature Range: -10 °C to +50 °C – suitable for most office environments
• Humidity Tolerance: 10 %–95 % relative humidity; ensures reliable operation in varying climatic conditions

Software & Management

• User Manual: Comprehensive guide available in multiple languages, covering setup, configuration and troubleshooting
• Firmware Updates: Delivered via USB or over the network; ensures the device stays current with security patches and feature enhancements
• Remote Management: Supports SNMP, RADIUS, LDAP integration for centralized administration in larger deployments
• Security Features: Supports IEEE 802.1X authentication, TLS/SSL encryption for SIP signaling, and secure firmware updates

Physical & Environmental Specifications

• Dimensions (packed): 246 mm × 223 mm × 120 mm – compact packaging for efficient shipping
• Weight (packed): 1.2 kg – lightweight for easy handling during installation
• Power Adapter: Not included; requires a compatible PoE source or external AC adapter with 5 V output and 1.2 A current rating
• Operating Voltage: Input: 100–240 VAC; Output: 5 VDC – standard for PoE devices

Why Choose the Yealink T42S?

The Yealink T42S combines a robust feature set with an elegant, space‑saving design. Its dual Gigabit Ethernet ports and PoE support simplify deployment in modern networks, while the extensive codec library ensures high‑quality audio across varying bandwidth conditions. With 12 programmable lines, comprehensive call handling features, and a user‑friendly interface, it is well suited for teams that require reliable communication without unnecessary complexity.

Whether you are upgrading an existing VoIP system or building a new infrastructure from scratch, the Yealink T42S offers the performance, flexibility and durability needed to keep your business connected.