Yealink SIP-T52S Administrator's Guide

Appendix
1075
Step
Action
Description
INVITE was successfully processed.
F16
200 OK—Proxy Server to User A
The proxy server forwards the 200 OK
response to User A. The 200 OK response
notifies User B is successfully placed on
hold.
F17
ACK—User A to Proxy Server
User A sends an ACK message to the
proxy server. The ACK confirms that User
A has received the 200 OK response. The
call session is now temporarily inactive.
No RTP packets are being sent.
F18
ACK—Proxy Server to User B
The proxy server sends the ACK message
to User B. The ACK confirms that the
proxy server has received the 200 OK
response.
F19
200 OK—User A to Proxy Server
User A sends a 200 OK response to the
proxy server. The 200 OK response
notifies that the connection has been
made.
F20
200 OK—Proxy Server User C
The proxy server forwards the 200 OK
message to User C.
F21
ACK—User C to Proxy Server
User C sends a SIP ACK to the proxy
server. The ACK confirms that User C has
received the 200 OK response. The call
session is now active.
F22
ACK—Proxy Server to User A
The proxy server forwards the SIP ACK to
User A to confirm that User C has received
the 200 OK response.
Call Transfer without Consultation
The following figure illustrates a successful call between Yealink SIP IP phones in which two
parties are in a call and then one of the parties transfers the call to a third party without
consultation. This is called a blind transfer. In this call flow scenario, the end users are User A,
User B, and User C. They are all using Yealink SIP IP phones, which are connected via an IP
network.

Yealink SIP-T52S Specifications

General

Touchscreen	-
Display diagonal	2.8 \
Backlight display	Yes
Display resolution	320 x 240 pixels
Lines quantity	16 lines
Phonebook capacity	1000 entries
Number of VoIP accounts	12
AC adapter input voltage	100 - 240 V
Bluetooth version	2.1+EDR
Security algorithms	802.1x RADIUS, HTTPS, MD5
Ethernet LAN interface type	Gigabit Ethernet
USB 2.0 ports quantity	1
Ethernet LAN (RJ-45) ports	2
Mounting	Desk/Wall
Handset type	Wired handset
Product type	IP Phone
Product color	Black
Voice codecs	G.722, G.723, G.723.1, G.726, OPUS, iLBC
Volume control	Digital
Operating temperature (T-T)	-10 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Cables included	LAN (RJ-45)
Number of handles included	1 pc(s)
Front camera	No
Operating system installed	Linux

Weight and Dimensions

Depth	212 mm
Width	211.6 mm
Height	166.8 mm