Interface between the Control Plane and the User Plane nodes
The present document specifies the Packet Forwarding Control Protocol (PFCP) used on the interface between the control plane and the user plane function.
PFCP shall be used over:
- the Sxa, Sxb, Sxc and the combined Sxa/Sxb reference points specified in 3GPP TS 23.214 [2].
- the Sxa' and Sxb' reference points specified in 3GPP TS 33.107 [20]. In the rest of this specification, no difference is made between Sxa and Sxa', or between Sxb and Sxb'. The Sxa' and Sxb' reference points reuse the protocol specified for the Sxa and Sxb reference points, but comply in addition with the security requirements specified in clause 8 of 3GPP 33.107 [20].
- the N4 interface specified in 3GPP TS 23.501 [28] and 3GPP TS 23.502 [29].
- the N4mb interface specified in 3GPP TS 23.247 [72].
In this specification the term CP function applies to control plane nodes such as SGW-C, PGW-C, TDF-C, SMF and MB-SMF.
In this specification the term UP function applies to user plane nodes such as SGW-U, PGW-U, TDF-U, UPF and MB-UPF.
The prefix PFCP in message and procedure names is used to indicate that messages and procedures are common and used on Sx, N4 and N4mb reference points. A PFCP session refers to both Sx and/or N4 sessions, or to an N4mb session. A PFCP association is established between a CP function and a UP function, i.e., for EPC, between an SGW-C/PGW-C/TDF-C and an SGW-U/PGW-U/TDF-U, and for 5GC, between an SMF and a UPF or between an MB-SMF and MB-UPF.
In the related stage 2 specifications the prefix Sx, N4 and N4mb is used for these common procedures realised by PFCP.
Clauses or paragraphs that only apply to EPC or 5GC are indicated by the label "for EPC" or "for 5GC".