Yealink SIP-T48U Administrator's Guide

Firmware Upgrade
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Firmware Upgrade
There are two methods of firmware upgrade:
l Manually, from the local system for a single device via the web user interface.
l Automatically, from the provisioning server for a mass of devices.
Note: We recommend that the devices running the latest firmware should not be downgraded to an earlier firmware version.
The new firmware is compatible with old configuration parameters, but not vice versa.
All configurations will be cleared on the T23P/T23G/T21(P) E2/T19(P) E2 phones when downgrading the phones from firm-
ware version 84 to 83.
Topics
Firmware for Each Phone Model
Firmware Upgrade Configuration
Firmware for Each Phone Model
You can download the latest firmware online: http://sup-
port.yealink.com/documentFront/forwardToDocumentFrontDisplayPage.
The following table lists the associated and latest firmware name for each device model (X is replaced by the actual
firmware version).
IP Phone Model Firmware Name Example
T57W/T54W/T53W/T53
(T5W firmware unified)
96.x.x.x.rom 96.85.0.10.rom
T48U/T46U/T43U/T42U
(T4U firmware unified)
108.x.x.x.rom 108.84.0.30.rom
T48S/T46S/T42S/T41S
(T4S firmware unified)
66.x.x.x.rom 66.84.0.80.rom
T48G 35.x.x.x.rom 35.83.0.30.rom
T46G 28.x.x.x.rom 28.83.0.30.rom
T42G 29.x.x.x.rom 29.83.0.30.rom
T41P 36.x.x.x.rom 36.83.0.30.rom
T40P 54.x.x.x.rom 54.84.0.60.rom
T40G 76.x.x.x.rom 76.84.0.60.rom
T29G 46.x.x.x.rom 46.83.0.30.rom
T27G 69.x.x.x.rom 69.84.0.80.rom
T23P/G 44.x.x.x.rom 44.84.0.60.rom
T21(P) E2 52.x.x.x.rom 52.84.0.60.rom
T19(P) E2 53.x.x.x.rom 53.84.0.60.rom
CP920 78.x.x.x.rom 78.84.0.80.rom

Yealink SIP-T48U Specifications

General

Handset type	Wired handset
Product type	IP Phone
Product color	Gray
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
Expansion module support	Yes
Ethernet LAN (RJ-45) ports	2
Display diagonal	7 \
Display resolution	800 x 480 pixels
Lines quantity	- lines
Phonebook capacity	1000 entries
Number of VoIP accounts	16
Voice codecs	AGC, AJB, AMR-WB, CNG, G.711, G.722, G.723.1, G.726, G.729ab, VAD, iLBC
Security algorithms	AES, HTTPS, SRTP, TLS
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Ethernet LAN interface type	Gigabit Ethernet
Front camera	-
AC adapter input voltage	100 - 240 V
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Keypad number of keys	29
Number of handles included	1 pc(s)
Harmonized System (HS) code	85171800

Weight and Dimensions

Width	226 mm
Height	185 mm