Appendix
443
3.
User B hangs up.
User A
Proxy Server
User B
F1. INVITE B
F2. INVITE B
F3. 100 Trying
F9. ACK
F10. ACK
F5. 180 Ringing
2-way RTP channel established
F8. 200 OK
F7. 200 OK
F6. 180 Ringing
F4. 100 Trying
F11. BYE
F12. BYE
F13. 200 OK
F14. 200 OK
Step
Action
Description
F1
INVITE—User A to Proxy
Server
User A sends a SIP 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.
Summary of Contents for Yealink SIP-T28P
Page 1: ......
Page 28: ...Administrator s Guide for SIP T2xP and SIP T19P IP Phones 12 ...
Page 76: ...Administrator s Guide for SIP T2xP and SIP T19P IP Phones 60 ...
Page 226: ...Administrator s Guide for SIP T2xP and SIP T19P IP Phones 210 ...
Page 238: ...Administrator s Guide for SIP T2xP and SIP T19P IP Phones 222 ...
Page 253: ...Configuring Security Features 237 ...
Page 265: ...Resource Files 249 ...
Page 279: ...Troubleshooting 263 ...