Overview

You have noticed an increase in SRIforSM requests coming with a GT from a phone network outside of your country which you believe could be fraudulent and you want to know if it is possible to block a GT from STP/HLR on the SMSC side. Since the SRIforSM arrives at the SMSC in the end due to the home routine, you want to add a rule to reject SRIforSMs arriving from this GT. 

Information

Yes, it is possible to block a GT on the SMSC side. To do this, follow the steps outlined below:

1. Login to MGR GUI
2. Go to the Routing > Routing Rules > SRISM Request menu and click Add new.
3. Define a name for the new rule.
4. Set the priority - it must have a priority higher than existing rules for Home-routed traffic.
5. Set the SCCP CgPA condition to a GT you would like to block as per the network from which you are receiving the fraudulent traffic.
6. Choose the desired Discard Action.
7. Save and activate it.
   
   
   

   Bear in mind that if the incoming SRI-SM is rejected, MT-fwSM is not received thus no CDR will be generated. However, Log records can be created if a logging profile is applied to the rule.