Product Overview
The VOIP KNSP-04L Loudspeaker Phone is designed with a robust aluminium alloy die-cast body, ensuring vandal and tamper resistance. It features a simple installation process and is equipped with a one-push button speed dial.

Audio and Visual Features
The device includes an external 30W loudspeaker made of metal with an impedance of 8Ω and a frequency response of 300-7000Hz, delivering a sound pressure level of 108dB. It also has a red flash light operating at 12V DC/10W for visual alerts.

Protection and Durability
The phone is protected against lightning as per ITU-T recommendation K.21 and offers excellent sound clarity. It is waterproof and dustproof, with a metal button and a self-closing door cover. The operational temperature range is from -40°C to +70°C.

Technical Specifications
The phone supports echo cancellation and allows for remote software upgrades, configuration, and monitoring. It offers an optional 7-minute timeout feature to release the line if the call is not ended by the other party.

Construction and Identification
The housing is powder-coated with a UV-stabilized polyester finish and covered with a reflective label for easy identification at night.

Applications
This device is suitable for use in tunnels, metros, railways, LRTs, speedways, marine environments, ships, offshore locations, mines, power plants, and bridges.

Specifications
The phone supports VoIP SIP2.0 with DTMF dialing, has an MTBF of 100,000 hours, and an MTTR of 2 hours. It allows free dialing with a maximum length of 16 digits and supports full duplex 2-way hands-free communication.

Power and Connectivity
It operates on Power over Ethernet (PoE) and local power options, with auxiliary contacts for additional connectivity. The network supports 10/100 BaseTX Ethernet with various IP and LAN protocols.

Certifications
The device complies with RCM, Australian communications, equipment safety standards, and EMC standards for railway applications.

Audio and Network Protocols
It supports audio codes G.711, G.722, G.729, and network protocols including IPv4, TCP, UDP, TFTP, RTP, RTCP, DHCP, and SIP. LAN protocols include PoE, WLAN, Network Access Control, STP, and RSTP.

Management and Operation
Programming is done through non-volatile flash memory with configuration via a Web GUI. It supports DHCP and static IP, remote software upgrades, centralized monitoring, and status LED indicators.