Yealink SIP-T52S Administrator's Guide

Administrator’s Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
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The call flow scenario is as follows:
1. User A calls User B.
2. User B answers the call.
3. User B transfers the call to User C.
4. User C answers the call.
Call is established between User A and User C.
User A Proxy Server User B
F1. INVITE B
F4. 180 Ringing
F6. 200 OK
F7. ACK
2-way RTP channel established
F23. 180 Ringing
F11. REFER
F12. 202 Accepted
F26. 200 OK
F2. INVITE B
F3. 180 Ringing
F5. 200 OK
F8. ACK
F22. INVITE C
F19. 200 OK
F27. ACK
F18. BYE
2-way RTP channel established
F9. REFER
F10. 202 Accepted
F17. BYE
F20. 200 OK
F21. INVITE C
F24. 180 Ringing
F25. 200 OK
F28. ACK
User C
Step
Action
Description
F1
INVITE—User A to Proxy Server
User A sends an INVITE message to the
proxy server. The INVITE request is an
invitation to User B to participate in a call
session.
In the INVITE request:

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