SMS Firewall

SMS Firewalls were originally introduced to secure mobile networks from vulnerabilities in SMS. Other networks have implemented firewalls that partially monetise SMS traffic, but are not fully secure. Cellusys SMS Firewall both secures and monetises your SMS traffic–properly.

This Tier 1 solution provides security against SMS spam, fraud, and other threats, increases revenue by blocking grey routes, and improves subscriber experience. This, in turn, reduces subscriber churn, and lowers customer service and call center costs.

The SMS Firewall receives all SMPP traffic, categorises messages according to content and takes action to block threats and grey routes.

Unified or Independent

SMS Firewall includes both SMS Analysis as well as SMS Home Router and is an answer to both SMS security and A2P monetisation.

The firewall directly intercepts ESME SMPP links as well as analysing all SS7-based SMS traffic. This includes all on-net and off-net messages.

SMS Firewall can be deployed standalone or can be complemented with additional protocols as additional modules of the Protect Unified Signalling Firewall as needed in the future.

Uses REST API integration

All Cellusys products support virtual deployment or can be installed on our customised servers


SMS Firewall defends mobile networks against all SMS-based messaging attacks and provides full protection and control over all messaging on the network. All messages are routed through the firewall, analysed, and classified. This means even those to outbound roamers are screened.

Spam events can be automatically detected and blocked. After a fraudulent or suspicious A2P SMS has been blocked, the message sender can be informed that their message was delivered, when in fact it has been removed from the network. Alternatively, grey or suspicious A2P SMS messages can be modified to include a warning to the recipient.

Home Router is key in protecting subscriber privacy by keeping their IMSI and location private.

SMS Aggregators

The middle is your business — make it flow. Our A2P solutions have helped many top SMS aggregators to eliminate grey routes, boost volumes, and open the floodgates on A2P revenues for their partner networks.  

Signalling Providers and Signalling Hubs

Signalling is your business — at least make it secure. We have provided many Tier 1 signalling hubs with the capability to control and secure their signalling.

Fast and Flexible

From the first day of deployment, pre-defined rules ensure all known threats are blocked. From here, the flexible classification engine, using advanced matching algorithms, not only detects the potential revenue leakage but also provides valuable intelligence in real time, assisting revenue assurance and security teams to actively stop any new, undefined threats or grey routes. 

New policies can be implemented immediately without relying on third parties or software updates. Users have full access to the protocol, and can easily customise the flexible rules engine via the user-friendly web interface to implement broad policies as well as attain fine-grained control.


SMS Firewall provides a complete A2P monetisation solution by classifying messages into A2P or P2P and subsequently blocking grey routes that appear. This  enforces A2P termination over official routes and eliminates revenue leakage. 

Take control over A2P traffic on your network by blocking SMS messages by bulk SMS providers and foreign operators until favourable commercial agreements are in place.

Accessible Reporting

Equipped with powerful (yet agile) reporting and alerting features, not only will your network be secure, you can be sure to have the most accurate information about your network traffic and security at your fingertips.

Customise real-time alerts to be notified the moment a threat occurs.

Everyone on your team can be provided proper access levels and customise reports to suit their individual needs (no matter their level of technical expertise) thanks to the intuitive GUI.

Easily set alerts or publish reports as broad as message logs or A2P Revenue Estimation or drill down to monitor a suspicious caller ID. Troubleshoot VIP SMS complaints and monitor message volumes with the touch of a button.


Cellusys provides SMS Home Routing according to the 3GPP TR 23.840 standard. It supports TCAP Handshaking on MT submission, and is 3GPP TS 33.200 compliant.

3GPP is a standards organization originally assembled with a goal of developing specifications for third generation (3G) mobile networks. Closely linked with GSMA they provide several industry standards and studies.

3GPP TR 23.840 originally released in 2006 has been updated with the latest version 7.1.0 released in 2007. It outlines how inter-PLMN architecture can be improved in terms of functionality as well as security.

3GPP TS 33.200 was released in 2001 and updated regularly with the latest version 7.0.0 released in 2007. This specification defines various security mechanisms necessary for the GSM MAP protocol.

3GPP TS 29.002 was released in 1999 and updated regularly with each new overall 3GPP release. This document details the operations, parameters and message flows used by the SMS.

Grey Route Test

How much A2P traffic are you missing?

Network Security Test

How secure is your network?

Learn more about our Managed Services for Security and A2P