Appendix
995
Step
Action
Description
Ringing response indicates that the user
is being alerted.
F20
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
F21
200OK—User C to Proxy
Server
User C sends a SIP 200 OK response to
the proxy server. The 200 OK response
notifies the proxy server that the
connection has been made.
F22
200OK—Proxy Server to User
A
The proxy server forwards the SIP 200
OK response to User A.
F23
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.
F24
ACK—Proxy Server to User C
The proxy server forwards the ACK
message to User C. The ACK confirms
that User A has received the 200 OK
response. The call session is now active.
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 the third party
with consultation. This is called attended 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.
The call flow scenario is as follows:
1.
User A calls User B.
2.
User B answers the call.
3.
User A calls User C.
4.
User C answers the call.
5.
User A transfers the call to User C.
Summary of Contents for CD860
Page 1: ......
Page 45: ...Getting Started 23 For SIP T42G T41P T40P Desk Mount Method Wall Mount Method Optional ...
Page 47: ...Getting Started 25 For SIP T23P T23G Desk Mount Method Wall Mount Method Optional ...
Page 122: ...Administrator s Guide for SIP T2 Series T19 P E2 T4 Series CP860 IP Phones 100 ...
Page 840: ...Administrator s Guide for SIP T2 Series T19 P E2 T4 Series CP860 IP Phones 818 ...
Page 995: ...Appendix 973 ...
