Appendix
983
The call cannot be set up successfully.
User A
Proxy Server
User B
F1. INVITE B
F2. INVITE B
F3. 180 Ringing
F4. 180 Ringing
F8. 200 OK
F7. 200 OK
F5. CANCEL
F6. CANCEL
Step
Action
Description
F1
INVITE—User A to Proxy
Server
User A sends an INVITE message to a
proxy server. The INVITE request is an
invitation to User B to participate in a
call session.
In the INVITE request:
The IP address of User B is inserted
in the Request-URI field.
User A is identified as the call
session initiator in the From field.
A unique numeric identifier is
assigned to the call and is inserted
in the Call-ID field.
The transaction number within a
single call leg is identified in the
CSeq field.
The media capability User A is
ready to receive is specified.
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. Proxy server forwards
the INVITE message to User B.
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 ...