School of Specs 23.501v20.2.0

3GPP 23.501 v20.2.0 — the document's own text

5.8.5.2 N4 Session Context

Taught in 13. Where the packets actually go (The 5G system architecture, in depth), 5. The connection, and what is promised on it (The 5G system architecture, overview).

N4 Session Context is identified by an N4 Session ID. An N4 Session Context is generated by SMF and UPF respectively to store the parameters related to an N4 session, including the N4 session ID and following information (see TS 29.244 [65] for an exhaustive list):

  • general session related parameters such as S-NSSAI, PDU Session Type, Trace Information, APN/DNN, ATSSS Control Information;
  • the PDRs, URRs, QERs, BAR(s), FARs, MARs used for this N4 session;
  • parameters sent to support UPF statistics.

The UPF may use parameters listed above in bullets 1) (e.g. S-NSSAI) and 2) (e.g. Network Instance in PDR/FAR(s)) for determining internal UPF resources.