Hi Experts.
I have one question:
In 5G NSA EN-DC, if UE make voice call, the data must be going through 4G leg, VoLTE traffic, no split at gNB.
If UE have both Voice + PS data, how these data come to UE, PS data can go through gNB or not?
During voice call, scell leg is released but gnb still keeps pdcp layer and RLC/MAC phy are with menb, therefore, PS data flows EPC -gnb-menb.
While voice is completely with menb.
It depend on configuration of vendor.
SCG may or may not release with VoLTE call.
If not released then data will go through NR air interface and voice through LTE.
We have option to have SCG addition or skip with VoLTE call.
look into specification and logs for ul data split bearer…there’s IE for it…
this IE decides how big of UL triggered data required to send Uplink in NR or Uplink in LTE.
It’s ENDC procedure.
Including VoLTE packets also VoIP packets over LTE / 5G…
This size of buffer supportability differ between handset makers or eNB gNB makers or carrier setting.
Thanks all.
I am confused. If VoLTE in NSA, anchor point of user plane is 4G eNB, path will switch from 5G gNB to 4G eNB.
In case data through 5G, voice through 4G, so have 2 anchor points of user plane.
eNodeB only.
If this, no data through 5G gNB?
Yes. Thats why it is dual connectivity (DC). Every bearer can be treated as MCG,SCG or split bearer individualy.
In this case, SN node is not released.
Voice from IMS → SGW → eNB.
PS data from Internet → SGW → gNB?
Yes, right.