Yealink SIP-T2XP Administration Guide

Appendix
221
Step
Action
Description
ACK message.
F7
302 Move Temporarily—Proxy
Server to User A
The proxy server forwards the 302
Moved Temporarily message to User A.
F8
ACK—User A to Proxy Server
User A sends a SIP ACK to the proxy
server. The ACK message notifies the
proxy server that User A has received
the ACK message.
F9
INVITE—User A to Proxy
Server
User A sends a SIP INVITE request to the
proxy server. In the INVITE request, a
unique Call-ID is generated and the
Contact-URI field indicates that User A
requests the call.
F10
INVITE—Proxy Server to User
C
The proxy server forwards the SIP
INVITE request to User C.
F11
180 Ringing—User C to Proxy
Server
User C sends a SIP 180 Ringing
response to the proxy server. The 180
Ringing response indicates that the user
is being alerted.
F12
180 Ringing—Proxy Server to
User A
The proxy server forwards the 180
Ringing response to User A. User A
hears the ring-back tone indicating that
User C is being alerted.
F13
200OK—User C to Proxy
Server
User C sends a SIP 200 OK response to
the proxy server. The 200 OK response
notifies User A that the connection has
been made.
F14
200OK—Proxy Server to User
A
The proxy server forwards the SIP 200
OK response to User A. The 200 OK
response notifies User A that the
connection has been made.
F15
ACK— User A to Proxy Server
User A sends a SIP ACK to the proxy
server. The ACK confirms that User A
has received the 200 OK response. The
call session is now active.
F16
ACK—Proxy Server to User C
The proxy server sends the ACK
message to User C. The ACK confirms
that the proxy server has received the
200 OK response.

Yealink SIP-T2XP Specifications

General

Brand	Yealink
Model	SIP-T2XP
Category	IP Phone
Language	English