Overview

Randomly, when an SMS is submitted to an SFR (French Operator) number, the SRI for B-Number is answered and has in the same TCAP the SRI result plus InformServiceCentre with mw-Status: sc-AddressNotIncluded (0280). Under these conditions, the MT is not sent but is instead stored in the queue. You want to know the reason behind why this occurs and if there is a way to configure the SMSC to send the MT under these conditions.

Solution

When MAP Phase Optimization (enablemapphaseoptimisation) is set to TRUE and Optimized MT Delivery (optimsedmtdelivery) is set to False, the SRI-SM will be sent on MAP phase 1 towards the HLR. In this situation, the Inform Service Centre is an unsupported operation. InformSC is only supported on MAP phases 2 and 3, and therefore the SRI-response containing an InformSC is discarded because you are receiving the InformSC operation on MAPv1, which is not allowed. 

You can try two options to resolve this issue.

Option 1:

• In the common_config file, where you see - optimisedmtdelivery="false", change it to "TRUE".
• Restart all RTR nodes with "tp_stop -p ; tp_start -p" commands, one node at a time.

Explanation: With setting the optimisedmtdelivery set to FALSE (current setting), it means the SMSC will ignore the HLR flags (MNRF, MCEF, MNRG) and will attempt an MT-fwd-sm even when one or more flags are set in the SRI-sm-response. When setting this parameter to TRUE, the flags are then taken into consideration, and in case any is set the MT-fwd is not attempted, and the message goes directly into the queue for a later attempt.

Option 2:

• In the common_config file, INSERT a new parameter right below the optimisedmtdelivery parameter mentioned above. This parameter should be - enablemapphaseoptimisation="false".
• After inserting this parameter (set to 'false'), restart all RTR nodes, one at a time, with "tp_stop -p ; tp_start -p".

Explanation: With ANY of the above changes, the SRI-SM that the SMSC launches towards SFR will not be on MAP phase1 anymore (but on phase2), and therefore the SRI-sm-response sent by the HLR will be accepted even when InformSC is inserted. The setting of enablemapphaseoptimisation to TRUE (current value/default) makes the SMSC use MAP version 1 whenever possible (depending on other configuration parameters). The goal of using MAP phase 1 transactions is to reduce the signaling capacity that is required for a MAP operation. So, if you set it to FALSE, the SMSC will not attempt to use MAP v1 when possible.