Voice over internet protocol (VoIP) phone systems allow you to turn almost any device into a mobile phone, be it a laptop, a tablet, or even a smartwatch. However, the flexibility of these devices also comes with inherent security risks that shouldn’t be ignored.

But it’s not always clear where these security risks come from, exactly.

VoIP calls travel over the internet, which exposes them to potential interception and eavesdropping from hackers. Without the proper security measures in place, sensitive conversations could be compromised. Not only does this pose risks to personal VoIP users, but it could also spell disaster for professional organizations dealing with sensitive customer and company information on a regular basis.

Luckily, most VoIP security concerns can be mitigated or eliminated by a few proactive measures.

How to Secure Your VoIP Phone System

While many VoIP providers come with features to protect against potential security threats, there are several steps that you can take as the user to secure your phone calls.

1. Use a VoIP Firewall

Setting up a digital firewall creates a barrier between your VoIP network and the public internet. This allows you to control incoming and outgoing traffic using preset security rules.

At a minimum, you need a firewall to protect your private VoIP system—but for better protection, you can use a dedicated VoIP firewall designed specifically to handle real-time voice and video traffic. SonicWall and Cisco VoIP firewalls are two popular options if you want to go this route.

Once you’ve selected a VoIP firewall, you can work with your provider to configure it properly by setting up individual ports and protocols. Some of these activities will include enabling stateful packet inspection, configuring your access control lists, and implementing network address translations.

If you’re not familiar with these security protocols, don’t worry. Most VoIP providers will offer assistance in setting up your VoIP firewall. Once that’s completed, all you need to focus on is regularly reviewing your firewall logs and testing for network vulnerabilities.

Remember, technology can’t do all the work for you. Establishing a tight firewall strategy tailored to your specific VoIP setup is crucial for your network’s security.

2. Install Anti-Virus and Anti-Malware Software

Most tech-savvy individuals already understand why antivirus and anti-malware software is important. It helps safeguard your devices from viruses, worms, and trojans that can exploit your network. Even worse, they can also attack any VoIP devices tied to an exploited server or device.

If you want to protect your VoIP devices from potential viruses and malware, you’ll first need to choose a reputable anti-virus software. If you want a solution designed specifically for businesses and enterprises, you should explore solutions like Symantec Endpoint Protection or Trend Micro. 

Once you’ve purchased your software, be sure to install it on all computers, laptops, servers, and other IT hardware associated with your VoIP system. Then, configure it to run regular scans on all device memory, programs, boot records, files, and networks. Not only will this safeguard your VoIP devices from potential viruses, but it will also alert you of any suspicious or abnormal activity in your network.

3. Use a VPS for Added Security

Using a Virtual Private Server (VPS) to host your VoIP phone system is another best practice for securing your VoIP network. A VPS adds an extra layer of protection by isolating your system from other shared networks, which could expose your devices to potential security risks.

Fortunately, there are several VPS providers that specialize in hosting VoIP systems. Some popular options include Vultr, Linode, and AWS.

Once you’ve chosen your VPS software, you can then work with your VoIP provider to install and configure your VoIP devices on your new private server. After your devices are set up on your VPS, you can tinker with access controls, firewalls, and other security measures to provide an extra layer of security for your devices.

The only other step you’ll need to take is actively monitoring resource utilization on your VPS. In other words, if you don’t have enough RAM or fast enough CPUs to support many concurrent calls on your network, you may need to upgrade your current VPS plan through your VPS provider. This is especially important for businesses that may increase their VoIP device usage as their company scales.

4. Enable VoIP Encryption

Potential hackers can’t exploit your sensitive information if they can’t understand it. This is what VoIP encryption allows you to do—it scrambles communication at both ends, keeping your calls, texts, and messages private as they travel between devices.

However, in order for this to work, encryption must be enabled on all your devices, including IP phones, softphones, gateways, and PBX systems. You should also keep in mind that true encryption is very technical, and the setup process varies from system to system. If you want to encrypt the messages on your VoIP devices, you should seek help from an expert or reach out to your VoIP provider to implement encryption in your network.

5. Restrict Unnecessary VoIP Traffic

If you’re trying to secure your VoIP devices, chances are there are certain users you don’t want accessing your network. Once your VoIP network is set up, you can leverage access control lists, VLANs, and other firewall tools to restrict unnecessary traffic.

Not only does this allow you to block individual users, but it also allows you to toggle access permissions for VoIP devices and applications. This is a great preventive measure for large companies who want to secure their business both inside and out.

6. Harden Your VoIP Servers

Hardening your VoIP server means protecting it against any vulnerabilities through a series of security tasks. Some of these tasks include changing your default passwords, disabling any unused network services, applying the latest OS security patches, and enabling alerts to monitor for security threats.

The best part about this step is that it doesn’t require any involvement from your VoIP provider. Instead, you can work with your server admin to run through each step.

7. Use Strong Passwords and Two-Factor Authentication

While it seems like an obvious best practice, many VoIP breaches occur due to weak passwords. To avoid these potential breaches, you should change the default passwords across your VoIP equipment, admin accounts, web portals, and any other access points to your network.

You can also use password generators like LastPass, Norton, and 1Password to ensure you’re using two-factor authentication and strong passwords to secure your devices.

Your VoIP Provider’s Security and Encryption Responsibilities

If you’re already using one of the best VoIP providers on the market, then many of the best security practices are already provided for you. However, if you’re still exploring your options, there are many security measures your VoIP provider should offer.

VoIP Encryption

Your VoIP provider should offer media and signaling encryption by default—but you shouldn’t stop there. To ensure maximum protection, ask your VoIP provider about the strength of its encryptions.

Ideally, your provider will be using AES (Advanced Encryption Standard) with 256-bit keys to provide robust security across your network. You should also ensure that your encryption keys are routinely regenerated to avoid potential decryption attempts from potential system hackers.

Security Standard Compliance

When selecting a VoIP provider, make sure your provider adheres to essential security control standards and frameworks. Some of the certifications you should be looking out for include the following:

SOC 2: SOC 2 reports demonstrate a provider’s controls for security, availability, processing integrity, confidentiality, and privacy. Maintaining SOC 2 compliance shows that your provider takes security seriously and that your sensitive information is in good hands.

PCI DSS: VoIP vendors that process credit cards must comply with the Payment Card Industry Data Security Standard (PCI DSS). This is especially important for businesses who need to ensure that their customer payment data is safe when completing transactions over VoIP devices.

ISO 27001: ISO 27001 certification validates a provider’s information security management system. It’s also worth noting that achieving ISO 27001 certification requires an accredited external audit of a provider’s information security management system. If your VoIP provider is ISO 27001 certified, you can rest easy knowing that your information is safe.

HIPAA: If you’re a healthcare organization, your VoIP vendor should comply with HIPAA requirements like encryption, access controls, audits, and breach notifications. If your VoIP provider is HIPPA certified, then they’ve met all the requirements created to protect your patient health information (PHI).

Security Policy Transparency

Finally, before choosing a VoIP provider, ask for details on security architecture, policies, audits, breach response plan, and other safeguards.

Security policy transparency should be treated as a non-negotiable when selecting a potential VoIP provider. If they are unwilling to share their policies around network security, you’ll be unable to determine whether or not your VoIP devices and overall network are going to be safe from potential hackers.

Special Considerations for Healthcare and High-Security Industries

High-security industries like healthcare and financial services deal with sensitive information on a daily basis. They also have the most stringent security requirements—like HIPAA for healthcare organizations.

Before choosing a provider, you’ll want to work closely with your potential VoIP vendor to ensure its security measures satisfy all regulations that are specific to your industry.

Ongoing VoIP Security and Encryption Best Practices

Securing your VoIP system isn’t a one-and-done deal. Once you’ve ensured that all security best practices are being met, you’ll want to conduct the following activities on an ongoing basis:

  • Regularly update your VoIP software, firmware, and OS for any system updates and upgrades
  • Scan and audit your system to identify any potential vulnerabilities or security risks within your network
  • Keep employees and anyone using your VoIP services up-to-date on the latest security protocols and best practices
  • Conduct a VoIP security and compliance review on an annual basis to ensure you’re meeting important industry regulations

Security for VoIP vs. Traditional Phone Systems

Most security professionals have a bias when it comes to VoIPs vs. landlines. While VoIP systems introduce new threats like DDoS attacks, network injections, and eavesdropping, landlines have their own vulnerabilities as well.

For instance, landline calls are not encrypted, making it easy for them to be intercepted and monitored. They also have weak PBX (Private Branch Exchange) security and no protections like anti-malware when compared to VoIP devices.

Ultimately, the benefits of VoIP outweigh the security risks if you’re following the industry best practices. As long as you go through the trouble of vetting your VoIP provider, you’ll have no problem securing your network and keeping sensitive company—and customer—information safe.