Key Features and Benefits:
Easy Customization and High Expansibility
The SIP-T48U has a seven-inch, 800 x 480-pixel, backlit- color touch screen, which enables a rich
visual presentation and easy navigation. Accompanied by two USB ports, the T48U is your right-hand
man in the office that makes Bluetooth, Wi-Fi, USB headset and USB recording possible, and you can
use any two of them freely according to your needs to enrich phone features. Meanwhile, the phone
not only has 29 one-touch DSS keys that can be easily programmed to various features, but also can
connect up to three expansion modules, for up to 180 additional buttons with a screen-based LCD
display and LED system.
HD Audio
Yealink Optima HD Voice technology combines cutting-edge hardware and software with wideband
technology for maximum acoustic performance. Being a totally open, highly versatile audio codec,
Opus, is designed to perform a higher HD audio quality than other wideband codecs in a high network
bandwidth; However, if your current network quality is poor, Opus can provide you with a better audio
quality than other narrowband codecs. And its hearing aid compatible (HAC) handset helps the
person who is with hearing loss to hear the voice more clearly.
Efficient Installation and Provisioning
Yealink T4U series supports efficient provisioning and effortless mass deployment with Yealink’s
Redirection and Provisioning Service (RPS) and Boot mechanism to help you realize the Zero Touch
Provisioning without any complex manual settings, which makes the T4U series simple to deploy,
easy to maintain and upgrade. Furthermore, a unified firmware and auto-p template that applies to all
T4U phone models, saves even more time and costs for businesses, as well as simplifies the
management and maintenance.
Secure Transport and Interoperability
Yealink T4U series uses SIP over Transport Layer Security (TLS/SSL), which is the latest network
security technology. It’s also compatible with leading soft switch suppliers, such as 3CX, Broadsoft
Broadworks. Moreover, it is carried with dual fimrware images that gives you a enterprise-level
protection to avoid bricking your system once upgrade failed.

Phone Features
> 16 VoIP accounts
> Call hold, mute, DND
> One-touch speed dial, hotline
> Call forward, call waiting, call transfer
> Group listening
> Emergency call
> Redial, call return, auto answer
> 10-way conferencing
> Direct IP call without SIP proxy
> Ring tone selection/import/delete
> Set date time manually or automatically
> Dial plan, XML Browser, action URL/URI
> RTCP-XR (RFC3611), VQ-RTCPXR (RFC6035