Call Transfer With Consultation - Yealink T46G Administrator's Manual

Step
Server
180 Ringing—Proxy Server to
F20
User A
F21 200OK—User C to Proxy Server
F22 200OK—Proxy Server to User A
F23 ACK— User A to Proxy Server
F24 ACK—Proxy Server to User C

Call Transfer with Consultation

The following figure illustrates a successful call between Yealink Skype for Business 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 consultative transfer. In this call flow scenario, the end users are
User A, User B, and User C. They are all using Yealink Skype for Business phones, which are
connected via an IP network.
The call flow scenario is as follows:
User A calls User B.
1.
User B answers the call.
2.
User A calls User C.
3.
User C answers the call.
4.
User A transfers the call to User C.
5.
Action
indicates that the user is being alerted.
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
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.
The proxy server forwards the SIP 200 OK
response to User A.
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.
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.
Appendix
Description
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