One PDU session mapped to multiple DRB

Hi, can anyone please help to share the example configuration where one PDU session is mapped to multiple DRB, and possible use case also?


Below is the brief description/basics about the Multiple DRBs per PDU Session:

  • Support for voice calls in NR SA
  • Setup of GBR QoS flow for voice using a dedicated DRB in the PDU Session for IMS Voice
  • Multiple DRBs setup per PDU Session
  • QoS Parameters Modification
  • RLC UM
  • Multiple QoS flows per Session in Mobility

Below are the Supported configuration or limit can be done:

  • 8 PDU Sessions / UE
  • 4 DRBs / PDU Session
  • 1 QoS Flow / DRB
  • 8 DRBs / UE (Baseband limitation)
  • One QoS flow with RTP and RTCP in one DR

Example for it:

Nice information.
Are these limitations from Standard?

All these are Standard limitations.

Hi, thanks for sharing the information.
I have one doubt here… I guess multiple QoS flow can be mapped to single DRB.

I see on few pictures in different article.
Even as per ASN, it seems multiple QOS flow can be mapped to one DRB as below:


Could you please double confirm on this?

Yes yes… You can map.
That can be done in UPF by SDF templates.

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