Analysing in an LTE network we found many TAU requests from UE that reports a very strange Old GUTI / EPS Identity with raw hex value 0b29071855102132713a8589
– Length is 11 octets (!!!)
– Type is 1 (IMSI)
– Content is something like 270815501122317A35898 (invalid, should be up to 15 BCD digits)
Any idea what this could be and how to prevent it from pummelling the radio network? This happens every 250ms for hours.
Yes happening in one cell and only one UE involved.
Checked the CAP file, NAS-PDU, etc.
Some interesting stuff. The EUTRAN-CGI shows correct MCC but MNC is Inactive. The EPS mobile identity – Old GUTI containing IMSI decodes to MCC in Europe and MNC in Indian? There is No TMSI identified. This UE is attempting combined TAU + IMSI Attach, yet not EMM connected?