Yealink SIP-T48U Administrator's Guide

Administrator’s Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones
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Initialization Process Overview
The initialization process of the device is responsible for network connectivity and operation of the device in your
local network. Once you connect your device to the network and to an electrical supply, the device begins its ini-
tialization process.
Topics
Loading the ROM File
Configuring the VLAN
Querying the DHCP (Dynamic Host Configuration Protocol) Server
Contacting the Provisioning Server
Updating Firmware
Downloading the Resource Files
Loading the ROM File
The ROM file resides in the flash memory of the device. The device comes from the factory with a ROM file pre-
loaded. During initialization, the device runs a bootstrap loader that loads and executes the ROM file.

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