SGA-IC

The ‘IMSI - IMEI Pair Collector’ service,
implemented by
TSP-Lab and AITIA

Table of contents

• Introduction

• System Overview

  • Hardware components

  • Software components

    • Monitor units

    • The Server

• Summary

Goals

• The association information of the subscriber’s mobile equipment ID (IMEI), the SIM card inserted to that equipment (IMSI) and the actual calling number of the subscriber (MSISDN) is often hidden before the eyes of the operator.
• This association information changes often for users who change their SIM cards inside their mobile phone on a regular basis.
• The actual IMEI-IMSI-MSISDN triplet can be gathered from the central GSM nodes (HLR, AuC, EIR), but this direct access is not always convenient.
• SGA-IC uses passive monitoring of certain central SS7 links to build the IMSI-IMEI database, where actual as well as historical association data can be looked up as well.
• SGA-IC is able to complete the MSISDN-IMSI database maintained by the operator using active HLR-enquiry on the actual MSISDN-IMSI association.
• SGA-IC solution is suggested for supporting fault management, traffic analysis, or applications such as mass MMS-sending, where the quality of the MMS to be sent out to an MSISDN depends on the mobile equipment capabilities (described by IMEI).

Operating principles

• Collects CheckIMEI messages by passive and distributed monitoring of EIR/AUC links
• Gets IMSI-IMEI pairs from CheckIMEI messages
• Stores pairs in a cache
• Loads collected pairs into an SQL database, when the IMSI-IMEI pair is
  • a new IMSI-IMEI pair
  • an existing one in the cache but it is too old
• All IMSI-IMEI pairs can be exported into a human readable *.sql file loading them into database manually
• Content of IMSI-IMEI cache can be deleted
• Note: Since monitoring SS7 links only IMEI-IMSI pairs can be collected, MSISDN-IMSI associations are accessible from subscribers' database of the operator

Miscellaneous functions

• Statistics
  • about signaling link traffic
  • about seen and stored IMSI-IMSI pairs in every fifteen minutes
• Alerting
  • about Sga-IC and the operating system
  • alarms are sent to network operator’s NOC by SNMP traps
• Logging
  • adjustable detail levels from ‘Off’ to ‘Debug’

Implications of the actual implementation

• Reliability
  • Complete duplication of whole system
    • just one click to switch to warm reserve in case of failure
• Database access
  • via standard SQL queries
• Components can be remotely maintained

What’s in the box?

• We provide:
  • SS7 monitors
    • telecom hardware + firmware, IT hardware + operating system, Sga-IC software
  • server complex
    • IT hardware (can be the same as the monitor's) + operating system, Oracle Client, Sga-IC software
  • cables
  • support

Operating conditions

• Followings should be provided by the GSM network operator:
  • monitoring points to all EIR/AUC SS7 links
  • optionally SNMP access to NOC
  • reliable and safe IP network connection points
  • 230 Volts AC power points
  • local system administrator(s)

Contact

• e-mail: pvarga@tmit.bme.hu
• telephone: +36-1-4538080
• fax: +36-1-14538081
• mobile-phone: +36-30-7484575