IMS Registration Sequence Diagram

This sequence diagram details the message interactions involved in IMS registration. IMS registration from a visited IMS network is covered. The interactions covered are:

  1. Terminal attaching to the GPRS Network.
  2. Terminal activates a PDP context.
  3. An unauthenticated IMS registration is attempted.
  4. IPSec security association is established between the User terminal and the P-CSCF.
  5. Finally the terminal performs an IPSec protected registration that completes the authentication of the network and the terminal.

We look at the registration via multiple views into the registration interactions: