Yealink SIP-T57W Administrator's Guide

Administrator’s Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones
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For example, if you set the Always Forward on code to be *78 (may vary on different servers), and the target number
to be 201. When you enable Always Forward on the IP phone, the phone sends *78201 to the server, and then the
server will enable Always Forward feature on the server side, hence being able to get the right status of the exten-
sion.
For anonymous call/anonymous call rejection feature, the phone will send either the on code or off code to the
server according to the value of Send Anonymous Code/Send Rejection Code.
The difference between RFC 2543 Hold enabled and disabled
Capturing packets after you enable the RFC 2543 Hold feature. SDP media direction attributes (such as a=se-
endonly) per RFC 2543 is used in the INVITE message when placing a call on hold.
Capturing packets after you disable the RFC 2543 Hold feature. SDP media connection address c=0.0.0.0 per RFC
3264 is used in the INVITE message when placing a call on hold.
The difference between Shared Call Appearance (SCA) and Bridge Lines
Appearance (BLA)
SCA and BLA are similar signaling methods that enable more than one phone to share a SIP line. The method you
use varies with the SIP server you are using. In the configuration files, the relevant configuration parameters of SCA
and BLA are different. The barge-in and call pull feature are not available with BLA, but they are available with
SCA.

Yealink SIP-T57W Specifications

General

Mounting	Desk/Wall
Handset type	Wired handset
Product type	IP Phone
Product color	Gray
Ethernet LAN	Yes
Wi-Fi standards	802.11a, 802.11b, 802.11g, Wi-Fi 4 (802.11n), Wi-Fi 5 (802.11ac)
Security algorithms	AES, HTTPS, MD5, SRTP
Networking standards	IEEE 802.11a, IEEE 802.11ac, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, 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	- lines
Phonebook capacity	1000 entries
Number of VoIP accounts	16
AC adapter input voltage	100 - 240 V
AC adapter output current	2 A
AC adapter output voltage	5 V
Volume control	Buttons
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Display diagonal	7 \
Display resolution	800 x 480 pixels
Front camera	No
Cables included	LAN (RJ-45)
Number of handles included	1 pc(s)
Voice codecs	G.722, G.723.1, G.726, G.729A, G.729B, iLBC

Weight and Dimensions

Depth	220 mm
Width	259.4 mm
Height	211 mm