Diameter Routing Function
SS7 Routing Function
Diameter Signaling Screening Function
SS7 Signaling Screening Function
Along with the telecom service development, the mapping between single subscriber id and its home UDC NE is becoming necessary. SLF determines the subscriber's home UDC NE according to its unique subscriber number (not according to subscriber number range).
BSF (Binding Support Function) implements the PDU session binding function for 5G users. In BSF, each PDU session stores the session binding information including user ID, DNN, UE address (IP address or MAC address), and PCF address selected by SMF. It provides the PCF address query service for AF or NEF to ensure that the AF can identify the UE's service based on the UE address, so that the N5/Rx interface messages can be routed to the corresponding PCF for the PDU session of the UE.
SEPP provides the following functions for 5G signaling protection:
• Topology hiding
• Message filtering
• Confidentiality protection of parameters (such as SUPI), etc.