C-77

User Agent to User Agent: Call Waiting
Figure C-27. User Agent to User Agent: Call Waiting — Diagram 2
VOCAL User Agent UA Marshal Redirect Server VOCAL User Agent VOCAL User Agent
16. INVITE
17. 100
18. INVITE
19. 302
20. ACK
21. INVITE
22. 302
23. ACK
24. INVITE
25. 180
26. INVITE
27. 200
28. 200
29. 200
30. ACK
31. ACK