Yealink SIP-T53W Administrator's Guide

Troubleshooting Solutions
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l Users are seated too far out of recommended microphone range and sound faint, or are seated too close to sens-
itive microphones and cause echo.
l Intermittent voice is mainly caused by packet loss, due to network congestion, and jitter, due to message recom-
bination of transmission or receiving equipment (for example, timeout handling, retransmission mechanism, buf-
fer underrun).
l Noisy equipment, such as a computer or a fan, may cause voice interference. Turn off any noisy equipment.
l Line issues can also cause this problem; disconnect the old line and redial the call to ensure another line may
provide a better connection.
There is no sound when the other party picks up the call
If the caller and receiver cannot hear anything - there is no sound at all when the other party picks up the call, the
possible reason could be: the phone cannot send the real-time transport protocol (RTP) streams, in which audio
data is transmitted, to the connected call.
Try to disable the 180 ring workaround feature.
Related Topic
Early Media
Play the local ringback tone instead of media when placing a long-dis-
tance number without plus 0
Ensure that the 180 ring workaround feature is disabled.
Related Topic
Early Media
Wi-Fi and Bluetooth Issues
The wireless signal strength is low
Ensure the IP phone and your gateway/ router are within the working range and there is no obvious interference
(walls, doors, and so on.) between them.
The phone cannot connect to Bluetooth devices all the time
Try to delete the registration information of the Bluetooth device on both IP phone and Bluetooth device, and then
pair and connect it again. Contact Yealink field application engineer and your Bluetooth device manufacturer for
more information.
The Bluetooth headset affects IP phone’s voice quality
You may not experience the best voice quality if you use a Bluetooth headset while the 2.4 GHz band is enabled or
while you are in an environment with many other Bluetooth devices. This possible loss in voice quality is due to
inherent limitations with Bluetooth technology.
Firmware and Upgrading Issues
Fail to upgrade the phone firmware
Do one of the following:
l Ensure that the target firmware is not the same as the current firmware.
l Ensure that the target firmware is applicable to the IP phone model.
l Ensure that the current or the target firmware is not protected.
l Ensure that the power is on and the network is available in the process of upgrading.
l Ensure that the web browser is not closed or refreshed when upgrading firmware via the web user interface.

Yealink SIP-T53W Specifications

General

Mounting	Desk/Wall
Handset type	Wired handset
Product type	IP mobile phone
Product color	Gray
Keypad illumination	Yes
Wi-Fi standards	802.11a, 802.11g, Wi-Fi 4 (802.11n)
Bluetooth version	4.2
Security algorithms	AES, HTTPS, SIPS
Networking standards	IEEE 802.1p, IEEE 802.1x, IEEE 802.3af
Ethernet LAN interface type	Gigabit Ethernet
Supported network protocols	FTP/TFTP/HTTP/HTTPS
Dual-Tone Multi-Frequency (DTMF) modes	In-band, Out-of band, SIP info
USB 2.0 ports quantity	1
Ethernet LAN (RJ-45) ports	2
Lines quantity	8 lines
Phonebook capacity	1000 entries
Number of VoIP accounts	12
AC adapter input voltage	100 - 240 V
AC adapter output current	1.2 A
AC adapter output voltage	5 V
Power consumption (typical)	2.3 W
Volume control	Buttons
Number of programmable keys	8
Storage temperature (T-T)	-30 - 70 °C
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Display diagonal	3.7 \
Display resolution	360 x 160 pixels
Cables included	LAN (RJ-45)
Number of handles included	1 pc(s)
Number of DECT wireless handsets	4
Voice codecs	G.722, G.723.1, G.726, G.729A, G.729B, OPUS, iLBC

Weight and Dimensions

Depth	210.6 mm
Width	212 mm
Height	174.5 mm