Bitrate Mapping across Diameter Interfaces

The SMF receives QoS values for uplink and downlink traffic in bits per seconds (bps) from PCRF.

If an APN-AMBR for uplink and the APN-AMBR for downlink are received from an interface other than the GTPv2 interface, the SMF converts the APN-AMBR for uplink and the downlink values in bits per second to kilobits per second. If this conversion results in fractions, then the value of APN-AMBR for uplink and the APN-AMBR for downlink gets rounded upwards.

By default, if the configuration isn’t configured, the SMF rounds off the bit rate to the CEIL value during conversion.

This feature impacts the following procedures:

  • 4G session establishment

  • Default bearer update over RAR/CCA-U