sipping-8----Page:4
1  2  3  4  5  6 

SUBSCRIBE B (contact A)
NOTIFY A (contact B)
200 SUBSCRIBE (contact B)
200 NOTIFY (contact A)
INVITE A (contact B)
183 (contact A’)
PRACK A’ (contact B)
200 PRACK (contact A’)
603 INVITE (contact mars)
NOTIFY ??? (contact B)
Is this A or A’?
All messages
in a single
shared dialog
PPT Version