Yealink SIP-T58V/A

Administrator’s Guide for SIP-T5 Series Smart Media Phones
808
Step
Action
Description
 The port on which User B is prepared
to receive the RTP data is specified.
F2
INVITE—Proxy Server to User B
The proxy server maps the SIP URI in the To
field to User B. The proxy server sends the
INVITE message to User B.
F3
180 Ringing—User B to Proxy
Server
User B sends a SIP 180 Ringing response to
the proxy server. The 180 Ringing response
indicates that the user is being alerted.
F4
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 B is
being alerted.
F5
302 Move Temporarily—User B to
Proxy Server
User B sends a SIP 302 Moved Temporarily
message to the proxy server. The message
indicates that User B is not available at SIP
phone B. User B rewrites the contact-URI.
F6
ACK—Proxy Server to User B
The proxy server sends a SIP ACK to User B,
the ACK message notifies User B that the
proxy server has received the 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.