Examiners may have noticed that the internet is flooded with secret or hack codes that may be entered into a handset and a brief description of the code's purpose. Every make and model seems to have its own codes. One code that has been doing the rounds since 2010 is the Blackberry Bold code for ' Display cause of PDP reject ' relevant to GPRS. Below is list of sample entry codes posted on the internet. As you can see there appears to be some variation in the way the code is expressed it should be entered into a Blackberry:
ALT+JKVV @ Home Screen. Display cause of PDP reject
http://newestblackberryfreeware.com/blackberry-tips-and-tricks/blackberry-secret-codes/
ALT-JKVV Home Screen Display cause of PDP reject
http://forum.mintywhite.com/viewtopic.php?f=9&t=790
ALT-JKVV Home Screen Display cause of PDP reject
http://forums.crackberry.com/archive/index.php?t-78665.html
ALT+JKVV @ Home Screen. Display cause of PDP reject
http://www.xusermanual.com/all-tags/blackberry-bold-3-secret-codes
It is recommended that examiners may wish to consider researching the use of the codes on test handsets prior to conducting 'live' examination on the evidential DUT.
However, a second matter that was apparent from the internet postings that there was no assistance given to the reader or, for that matter, an examiner as to the interpretation of the information (data) that would be displayed on the screen of the DUT as a value or a cause that would be relevant to it (the value).
In order to understand the meaning of the data relevant to ' Display cause of PDP reject ' examiners should at first instance review 3GPP TS24008 / GSM 0408 in order to understand the relevance of PDP with respect to 'Activate PDP Context Reject State ' when it is On and the value given in an ' Activate PDP Context Reject SM Cause '.
Below are several tables compiled with content relevant to PDP reject values and their causes. Whilst I have reviewed standards and other sources to seek agreement of the values and causes, you may wish to check for yourself the accuracy of the information recorded in the tables. The 3GPP/GSM standards have been identified above and to conduct simple Binary/Hex/Decimal conversion readers may wish to visit an online calculator website similar to the one at the following link http://easycalculation.com/binary-converter.php.
GMM Cause Information Element
SM Cause Information Element
SM Cause Information Element on GTP protocol
Whilst the values and causes in the tables above have been identified there is still additional information that the standards identify relevant to each of them. Having said that, being able to investigate these values/causes and trace them to the GSM MS / WCDMA UE and to the network is quite helpful, particularly when dealing with blacklisted handsets or invalid IMSIs. Additionally, the values and causes provide a useful guide when conducting live tests for GPRS cell site analysis.
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