Overview

You are trying to apply home routing to ported-out (MNP) subscribers to another operator, but there has been no response from your SMSC to the external party GT.

The traces and logs show that the RTR is forwarding the first SRI-SM request received from the foreign SMSC to the second operator SMSC, but not responding back to the international GT after receiving the SRI-SM response.

• Trace showing SRI request sent back to the other telecom operator's GT received on the SRI response:

Solution

This issue happens when the firewall is configured to perform SRI republishing for the other operator network. The SRI-SM Republishing functionality handles scenarios in which multiple networks within a country have deployed an FWL, and at least one of the networks deployed its FWL before deploying the signaling relay function for mobile number portability (MNP/SRF).

Republishing means that, instead of relaying a SendRoutingInfoForSm response from the HLR to the SMSC, the firewall reissues the SendRoutingInfoForSm request to the HLR with some changes to the SCCP address.

When the FWL receives a SendRoutingInfoForSm response from the HLR for a request from a suspect SMSC, it inspects the IMSI. If the IMSI does not identify a subscriber of the HPLMN, the FWL concludes that it represents a ported-out subscriber. If the subscriber is a member of the firewall's list of networks to which republishing applies, the firewall republishes the SendRoutingInfoForSm request.

This can be confirmed by checking if the 'firewallrepublishsrismnetworks' command has a defined value ("<country_code>-<network_name>") in the configuration file. For more information, please refer to the RTR Operator Manual found in the NewNet Download Center.