SMS Firewall & Messaging Security

SMS remains the channel that fraudsters, spammers and grey-route operators target hardest, because it reaches every handset and carries the passcodes that guard bank accounts. Dollu's SMS firewall gives mobile operators, MVNOs and large enterprises the visibility and control to stop that abuse: every message crossing the interconnect or the enterprise sender is inspected in real time, classified and either delivered, blocked, throttled or flagged according to policy - with decisions taken inline in under 50 milliseconds.

For operators, the firewall sits at the SS7 and SMPP edges of the network. It detects grey routes - international A2P traffic disguised as person-to-person to avoid termination fees - through signalling analysis, sender and SMSC address validation, volume patterns and content fingerprints. It closes spoofing of subscriber and enterprise sender IDs, identifies SIM farms and SIM-box clusters generating artificial traffic, and blocks smishing campaigns by analysing URLs, brand impersonation and message templates. Blocked grey traffic is redirected to contracted A2P channels, converting leakage into revenue.

For enterprises and brands, the same engine protects outbound messaging: it prevents your registered sender IDs from being spoofed on our network, filters outbound content against regulatory and carrier policies before it can be blocked downstream, detects OTP-pumping and artificially inflated traffic against your account and reports on impersonation attempts targeting your customers. Banks, payment providers and government agencies use it to keep the SMS channel trustworthy for the people who depend on it.

The firewall is a managed service. Dollu's messaging security team maintains the threat intelligence - global sender ID registries, malicious URL feeds, SIM-farm signatures and content classifiers updated hourly - tunes rules to each customer's traffic profile and monitors alerts around the clock from our SOC. Deployment options include a hosted service, an on-premises virtualised appliance for operators with data-residency requirements, and a hybrid model where policy is central and enforcement is local.