CelcomDigi has enhanced its network safeguards against scam calls by introducing a voice firewall that detects and flags suspicious calls in real time before customers answer them. The initiative provides an additional layer of security for over 20 million subscribers nationwide.
The voice firewall technology is fully embedded into CelcomDigi’s core network to provide visibility over incoming call activity.
By monitoring network traffic, the system analyses traffic patterns and risk indicators to identify fraudulent calls before they reach users. This new capability complements CelcomDigi’s existing SMS firewall, which filters malicious and prohibited text messages at the network level.
Over 355 million suspicious calls detected during pilot
During a recent pilot phase, the voice firewall detected 355 million malicious and suspicious call attempts, which included 217 million robocalls.
Following its nationwide rollout in July, incoming calls identified as risky now trigger a “Suspected Scam” alert on customer phone screens to help users make informed decisions.
According to CelcomDigi Chief Technology Officer Kesavan Sivabalan, intelligent networks must evolve beyond providing fast connectivity to identify and respond to emerging threats immediately. He stated that building greater intelligence into the network allows the telco to intervene earlier and help customers make safer choices through continuous investments in security.
The deployment forms part of CelcomDigi’s broader scam mitigation approach under its A.C.T. framework, which focuses on driving Awareness, maintaining internal Compliance to support law enforcement, and applying Technology against cybercrimes. The telco also continues its digital safety efforts through its flagship S.A.F.E. Internet programme and nationwide public awareness campaigns.
How CelcomDigi’s voice firewall intercepts scam calls
A voice firewall is a protective system that safeguards users through automated detection methods running directly within the network signalling layer.
It functions by monitoring voice network activities for suspicious behaviour, managing call traffic based on security policies, keeping records of voice interactions, and preventing unauthorised access to stop digital threats such as scam calls.
In CelcomDigi’s deployment, the technology’s advanced capabilities are embedded directly into its core network to provide visibility into call activity. This structure allows the system to analyse traffic patterns and risk indicators with high precision, identifying malicious and fraudulent activity before it reaches subscribers.
This new voice protection directly complements CelcomDigi’s existing SMS firewall technology.
While the voice firewall inspects incoming calls, the SMS firewall continues to detect and filter malicious and prohibited text messages at the network level.
Why network level defence is essential
Traditional spam protection methods rely on simple blocklists. Scammers can easily bypass these list based systems by constantly changing or impersonating phone numbers.
Network level defence replaces basic blocklists with active cybersecurity checks that authenticate caller identity, inspect traffic data, and analyse audio streams in real time. This approach neutralises social engineering threats automatically before human interaction occurs.
Other local telcos implementing network protection
CelcomDigi is not alone in upgrading network level defences. Other telecommunication providers in Malaysia have also implemented similar measures to tackle scam calls and text messages.
Maxis recently introduced an artificial intelligence powered firewall designed to block scam SMS and phone calls. U Mobile has likewise integrated Cellusys network level scam protection to shield its users from fraudulent communications.
