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Appendix
865
Call is established between User A and User C.
User A
Proxy Server
User B
User C
F1. INVITE B
F2. INVITE B
F3. 180 Ringing
F8. ACK
F9. INVITE C
F10. INVITE C
F11. 180 Ringing
F12. 180 Ringing
F13. 200 OK
F14. 200 OK
F15. ACK
F16. ACK
F4. 180 Ringing
F5. 302 Move Temporarily
F6. ACK
F7. 302 Move Temporarily
2-way RTP channel established
Step
Action
Description
F1
INVITE—User A to Proxy
Server
User A sends the 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.
Summary of Contents for Yealink SIP-T42G
Page 1: ......
Page 12: ...Administrator s Guide for SIP T2 Series T19 P E2 T4 Series CP860 IP Phones xii ...
Page 20: ...Administrator s Guide for SIP T2 Series T19 P E2 T4 Series CP860 IP Phones xx ...
Page 41: ...Getting Started 21 For SIP T46G Desk Mount Method Wall Mount Method Optional ...
Page 43: ...Getting Started 23 For SIP T29G T27P Desk Mount Method Wall Mount Method Optional ...
Page 45: ...Getting Started 25 For SIP T21 P E2 Desk Mount Method Wall Mount Method Optional ...
Page 678: ...Administrator s Guide for SIP T2 Series T19 P E2 T4 Series CP860 IP Phones 658 ...