Voice over LTE (VoLTE)

In this lesson you will learn that, for the UE to make a voice or a video call,

  • The UE first creates a default EPS bearer with QCI=5 that connects the UE to the IMS PDN.
  • And after exchanging signaling messages between the UE and the IMS network, the network will create a dedicated bearer with QCI=1, or QCI=2, in order to pass the media streams of the call into this dedicated EPS bearer.