• Home
  • 5G SA Call Flow Verification

Tech Paper: 5G Call Flow Verificaiton

5G SA Call Flow Verification

5G SA Call Flow Verification

The verification is based on PCAP files captured on RAN interfaces e.g. F1-, E1- and NG-Itf. The Protocol Engine converts encoded byte streams to JSON format and includes 2nd stage decoding for imported protocol elements. Call Trace functionality identifies messages belonging to a certain call flow based on various identities, such as CRNTI, DU/CU/UP/AMF UE ID, TMSI, IMSI … Various triggers, assigned to a set of messages during protocol extensions, are fed into State Machines for CU interfaces. This allows to mark failed or suspicious calls and display the result to the user in a customized representation.


  • Protocol Engine for Message Decoding
  • Call Trace functionality
  • State Machines to verify message sequence an call basis
  • Events added based on logged events during execution
  • Grahical representation for message flow and logged events


Failure analysis is a cumbersome task due to high volume of data to be processed and different event sources to be correlated. A grahical representation is the most convenient way to present events and call flows. Various filters allow to narrow down the messages excahned to the interesting points.


  • Automatic call instanace identification
  • Errenous or suspicious message sequences isolated
  • Message flow enriched by logged events
    Page: /