Having dealt with in-depth analysis of SS#7, GSM and GPRS networks I started to monitor
UTRAN interfaces approximately four years ago. Monitoring interfaces means decoding
the data captured on the links and analysing how the different data segments and messages
are related to each other. In general I wanted to trace all messages belonging to a single
call to prove if the network elements and protocol entities involved worked fine or if there
had been failures or if any kind of suspicious events had influenced the normal call
proceeding or the call’s quality of service. Cases showing normal network behaviour have
been documented in Kreher and Ruedebusch (UMTS Signaling. John Wiley & Sons, Ltd,
2005), which provides examples for technical experts investigating call flows and network
procedures.
