GSM Test Equipment

Some nice little bits of GSM test equipment that have recently fallen in to my hands courtesy of eBay!

Firstly a Sequoia SWGPRS023 Signal Strength Tester for GSM/GPRS Network Coverage. Details here:


This little device allows detailed interrogation of 2G GSM cell sites on the 850, 900, 1800, 1900MHz bands which are detected within range.

The information returned about cells includes:

  • The Absolute Radio Frequency Channel Number (ARFCN)
  • The Base Station Identity Code (BSIC) which identifies the BTS beacon frequency
  • The FSSI Signal Strength in dBm (decibels referenced to 1mW)
  • The Local Area Code (LAC) which identifies the area in which the cell is situated
  • Mobile Country Code (MCC)
  • Mobile Network Code (MNC)


Secondly an Anritsu MT8801B Radio Communications Test Set with options 02 (SG Local), 07 (Spectrum analyzer) and option 15 / MX880115A (GSM Measurement and Call Processing Firmware) fitted. Just in case Mrs. R finds out it did cost a LOT less than the $50K list price back in 1999!


With the GSM option various GSM frequency bands are supported. These include:

  • GSM450
  • GSM480
  • GSM710
  • GSM750
  • Trunking GSM (T-GSM-810)
  • GSM850
  • Primary GSM (P-GSM)
  • Extended GSM (E-GSM)
  • Railways GSM (R-GSM)
  • Digital Cellular Service (DCS1800)
  • PCS1900

Of course in the UK we are only really interested in GSM-900 and DCS-1800 bands. e.g. ARFCN 0-124 and ARFCN 512-885.


The GSM option call processing functionality supports GSM connection tests such as Location registration, Terminal call origination, Network call origination, Network disconnect and Terminal disconnect.


Also there is a frequency hopping function that changes the channel (ARFCN) used for communication between the base station (BS) and mobile station (MS) by each 4.62 ms frame. Frequency hopping is operated by the Measure Channel and Frequency set value of hopping frequency table-ARFCNs



VoIP Infrastructure Security

How secure is your VoIP Deployment?

There are lots of approaches to securing VoIP networks including the deployment of firewalls,
Session Border Controllers (SBC), encrypting SIP with TLS and voice with SRTP. But have you ever
considered an attack from the inside and in particular the integrity of the firmware running on each
IP Phone? If not I strongly recommend taking 55 minutes to watch the following on YouTube:


Converting IRD Strategies to Visio (UPDATED)

As a Happy New Year gift to the Genesys community I’ve decide to release the binaries associated with these blog posts in to the wild!

Hopefully somebody will find my Strategy Analyser useful!

Please note that this is beta code and that not all IRD blocks / block properties are implemented. Also the layout still needs some work.

You can download it here:


Just to let you know that a couple of testers have reported the same problem. COM exception (0x86DB0904). It is possibly a Visio 2003 interop issue which I am trying to get to the bottom off. In the meantime if anybody wants a strategy converting then please just email the XML export to me:


A quick video of Strategy Analyser in action on YouTube here:

This just shows dropping some XML exports into it and then converting them to Visio in real-time. I’ll post a video of the online mode when a get some time.


YouTube video of online mode:


Hopefully the problem reported by testers in France, Germany and Brazil has now been fixed. Version 1.7 is available for download here: