How it Works

The functionality of the Multiple N4 Interface feature involves:

  • Single UPF has multiple N4/Sx interface associations with each SMF.

  • There is no slicing of configuration in UPF per individual SMF.

  • The ECS/ACS configuration at the UPF is a union of all the individual SMF-specific configurations. For example:

    SMF1 has rulebase RB1 and no RB2.

    SMF2 has rulebase RB2 and no RB1.

    The UPF has both rulebase, RB1 and RB2 to cater the sessions from RB1 and RB2.

  • A maximum of four SMF peers are connected to a single UPF.

  • Overlapping IP pools from multiple SMFs are segregated based on the VRF ID.

  • Individual N4 association release purges sessions of the impacted SMF peer.

  • UPF redundancy works seamlessly.

  • In rare instance of any conflict among different SMF configurations, it will not be resolved at the UPF and will be installed in the sequence in which such CLIs were configured.