3GPP-SGSN-MCC-MNC, it should be defined in Wireshark Dictionary xml file TGPPGmb.xml
This issue was migrated from bug 3199 in our old bug tracker.
Original bug information:
Reporter: Alexander Gong
Status: RESOLVED FIXED
Product: Wireshark
Component: GTK+ UI
OS: Windows XP
Platform: x86
Version: 1.0.4