The subsystem allows collecting various information by analyzing signaling network traffic. Information collected includes failed calls and subscribers’ location updates. To obtain this, data alternative sources of information can be used (extended CDR and MSS special functionality). SS7 traffic analyzer allows receiving them all together and in the simplest way.
Location updates are registered in more cases comparatively to CDRs. Events for which location is available include:
- Periodic location update (periodical update of subscriber location information in case of no activity for long time);
- IMSI Attach (when LAC / SAC changes);
- IMSI Detach (when mobile device is switched off);
- Paging (subscriber location information update during incoming or outgoing call, receipt or sending SMS);
- Handover (subscriber location information update when Cell ID is changing during the call);
To analyze signaling network traffic 2*10GbE and 4*10GbE nodes are used, a number of SS7 protocols are supported: SCTP, MTP3, SCCP, BSSAP, RANAP.
Traffic SS7 (SIGTRAN), duplicated using SPAN ports, TAPs or specialized network appliances (Gigamon, NetOptics) is used as data source. In case it is not possible to access signaling traffic, collection of information is possible from alternative sources:
- Failed calls information can be obtained by enabling extended CDR functionality on MSS.
- Location update data for Nokia Siemens Networks switches can be received from a UDP stream, enabled as an additional function of MSS (subscriber data feed from VLR).
Collected data and queries
For location updates the following information is collected:
- Time of event;
- Subscriber’s MSISDN, IMSI, IMEI;
- LAC (Location Area Code);
- Cell ID;
- Switch number;
- Event code;
Collected data for failed calls is practically identical to regular calls in CDR files. Subscribers’ identifiers and base station queries are supported;