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How Secure Is VoIP? The Definitive Guide To VoIP Security

Want to reap the benefits of VoIP phone systems but worried about VoIP security? Here we’ll break down everything you need to know about VoIP reliability, common threats, and steps to keep your organization's data safe, including choosing a reliable phone provider.

VoIP phone systems are quickly becoming the top choice for most businesses for good reason. With cost savings, greater flexibility, and remote work capabilities, it is an effective and efficient solution for businesses of all sizes.

Any internet-based technology, however, raises security concerns.

You may wonder if VoIP is secure and what you can do to ensure your organization's data remains secure and private. This is even more important when your industry has strict regulations and security requirements.

In this guide, we’ll help you understand how VoIP data and security work, possible threats and how to reduce security vulnerabilities, including choosing a reputable and secure VoIP provider.

Why Is VoIP Security So Important?

Maintaining the integrity of your calls requires VoIP security. The last thing you want is hackers listening to your conversations without your knowledge and gaining access to private information from your business and clients. Information of this type can be used to harm a business's reputation.

Hackers can also try to gain access to PIN codes, accounts, health or payment information that they will use for theft, financial fraud, or to place expensive international calls on your business’ dime.

Because VoIP allows users to access their phone system and data from anywhere with an internet connection, you can make calls from your desk phone, a web-based softphone, or an app on your mobile device. This feature is incredible for productivity but it’s vital that credentials and login information are highly secured to protect data and information.

Ranking Security: VoIP Vs Landlines

It is important to remember that no system is entirely safe or impenetrable. If you’re considering the security differences between landlines and VoIP, you must first understand how they work.

Traditional Landline Security:

Traditional phone systems are physical, and calls are made via analog signals sent over copper wires that connect with the public switched telephone network (PSTN).

Due to the physical nature of traditional phone systems, eavesdroppers can use specialized equipment to tap into the lines and listen to conversations; this is called wiretapping. It is costly and difficult to guard against this sort of physical breach.

VoIP Reliability and Security

Voice-over-IP (VoIP) is a digital system that allows you to make and take voice calls using the internet. When you make a voice-over IP call from your business, audio is converted into digital data packets. These 'packets' will travel through the internet and switch back into audio when the call reaches your recipient.

Hackers can try to intercept these packets. But it’s important to note that with VoIP, many security features are in place to keep calls secure.

In addition, it’s very difficult to extract actual audio from encrypted packets without being the one who initiated or accepted the phone call.

It’s not possible to just open a data pack and look at what’s inside. Packets are related to each other, and information from those packets is exchanged with each other. So unless a hacker gets the whole picture, they won’t get anything. The system is designed so that they cannot get the complete picture.

While landlines may seem more secure, VoIP has technology, features, and measures in place to protect your data that landlines simply cannot match.

5 VoIP Security Threats: Signs and Prevention Tips

VoIP security threats and attacks typically don't target the VoIP infrastructure itself. Many of the attacks and threats are similar to what is carried against users of landline systems.

Here we’ll cover five common threats that can impact VoIP security, the signs that your system may have been breached, and how you can protect your business and its phone system.

Voicemail Hacking:

It is possible to check messages, change greetings, and modify settings remotely on most voicemail platforms. Normally, you would call into your voicemail platform, enter a PIN and access your voicemail inbox.

Hackers can try to guess your voicemail password and gain access to your organization's voicemail system.

From there, there are a couple of things they can do.

Hackers can modify the outgoing voicemail messages to say you will “accept the collect call charges.” In this case, they will dial the number using a collect call, and the call will connect because of the voicemail greeting. Once connected, the hacker can use the connection to forward calls internationally, which are then charged to the business.

Hackers can alternatively break into your voicemail and change your call forwarding and routing strategies to connect to expensive international phone numbers.

Signs Of Voicemail Hacking:

  • An unusually high number of international calls.

How To Prevent Voicemail Hacking:

  • Change your default password.

  • Choose a secure voicemail pin. Don't choose ordered numbers like 1234 or consecutive repeating numbers like 4444, dates, or addresses.

  • Require employees to change passwords on a regular basis.

  • Disable international calling if it is not required for your organization.

  • Have employees check and change greetings regularly.

  • Review call logs and check for unusual usage or long-distance charges.

Net2phone Security:

net2phone prevents users from creating weak PINs by preventing PINs that are ordered numbers or consecutive repeating numbers. We also do not allow calls to be forwarded to an external international phone number from the menu options.

Toll-Free Fraud:

Toll-free fraud can impact any business that uses a toll-free phone number. With toll-free fraud, attackers typically create fake telephone companies or make a profit-sharing agreement with owners of expensive international phone numbers, known as international premium rate number (IPRN) providers. After placing a high volume of calls, they can collect the revenue generated by the calls.

The attackers will navigate the auto-attendant menu and make sure the call never connects to a live agent, resulting in long and expensive calls.

Signs Of Toll-Free Fraud:

  • Huge monthly bills.

How To Prevent Toll-free Fraud

  • Ensure your system prevents prolonged periods on the auto-attendant if no one answers.

  • Avoid making your toll-free number point to an auto-attendant if you can.

  • You can configure the call to forward to voicemail or drop the call if no key is pressed.

  • Use 2FA (Two Factor Authentication) on your account

Net2phone Security:

net2phone allows a maximum session of 30 minutes for toll-free calls that connect to an auto-attendant. The call will end if it goes unanswered. To prevent incoming spam, we also limit the number of calls your toll-free number can accept at once.

Compromised Credentials

Compromised credentials occur when a hacker or third party can obtain your password and credentials and log into your account to make long-distance calls or modify your account settings, like your call forwarding rules.

Signs Of Compromised Credentials

  • Higher than normal usage.

  • Lots of unknown numbers in the call history.

  • Calls made outside of business hours.

How To Prevent Compromised Credentials

  • Regularly change passwords.

  • Use strong passwords that are at least 8 characters or more and include numbers and capital letters.

  • Use Multi-Factor Authentication

  • Review your phone bill at the end of each month.

Net2phone Security:

net2phone automatically blocks international calls to destinations that cost more than 40 cents a minute. Setting a rate limit helps to minimize the risk of someone gaining access and making unauthorized calls to high-cost areas.


This is similar to phishing which is done through email and tries to get victims to click malware links. Vishing attacks occur when scammers call you and try to extract personal information like financial, account, or personal details that they can use to hack your system. They will pretend to be trusted figures like someone from the bank, tech support, delivery services, and more. The hackers could use this information to log in to user accounts and place expensive long-distance calls.

Signs of a Vishing Attack

  • Unexpected phone calls from known companies.

  • People contacting you with urgency, pressure, or threats to suspend accounts.

  • People who are using pressure tactics to convince you to make immediate payments.

  • Callers who are asking a lot of personal questions, like your address or pet's name.

  • Unusual phone numbers on caller ID.

Preventing Vishing Attacks:

  • Don’t share sensitive information or personal information over the phone.

  • Regularly train employees on security and prevention measures.

DDoS Attacks (Distributed Denial of Service):

A distributed denial of service attack is an attack that floods a server with thousands upon thousands of requests to the point that the server can no longer handle normal traffic, making it inaccessible to its users.

This type of attack is not specific to VoIP but is a common attack that can happen on any web service. Typically the motive of this attack isn’t financial but more to harm the business or reputation of the target. With a cloud-based solution, the DDos attack will occur on the provider's end, not your business’ end. That’s why your VoIP service provider needs to have DDoS mitigation techniques in place.

Signs of a DDos Attack:

  • Issues and slowing down of services and phone system.

Net2phone Security:

net2phone has DDOS attack mitigation which would shut down the server under attack and revert all lines to our secondary site, similar to if we were to experience a power outage. This mitigation ensures no client’s communications suffer from a compromised system.

What To Look For When Choosing a Secure VoIP Provider

Part of ensuring a secure VoIP system for your business is choosing the right provider. Here are some things to consider when choosing a new VoIP business phone provider.

Encrypted VoIP

VoIP encryption is the process of encoding data into a secure format to prevent unauthorized access. Select a provider that encrypts its servers and stored data. This stored data, referred to as at-rest data, tends to be targeted by attackers more than transit data.

If you need data encryption, look for SRTP and TLS encryption for in-transit data. This is important for organizations that handle sensitive information like healthcare, financial services, or government agencies.

  1. Transport Layer Security (TLS): SIP (session initiation protocol) is the language that the phone speaks to talk to the server. TLS is that language encrypted. TLS encrypts data during transmission, and only the sender and receiver have the necessary keys to decrypt the information.

  2. Secure Real-Time Transport Protocol (SRTP): Similar to TLS, SRTP is the protocol that encrypts the voice and audio packets that are being sent back and forth in a VoIP call.

Can They Help With Regulatory Compliance?

If your industry requires regulatory compliance, make sure the provider you choose supports compliance. Having the right accreditations or providing compliance tools is part of this process.

HIPAA : If your US-based organization is a covered entity under HIPAA, ensure that your VoIP provider offerings comply with HIPAA regulations. HIPAA-compliant phone service can include call recording, voicemail, and voicemail transcription features to safeguard your valuable information.

PIPEDA: In Canada, any organization that obtains, uses, or discloses personal information for commercial purposes needs to comply with PIPEDA. Because with VoIP, voice is data, look for a provider that keeps your data in Canada on Canadian servers, amongst other things.

PCI Compliance: (Payment Card Industry) is necessary for any organization that accepts, transmits, or stores credit card information. If you take credit card information over the phone, choose a VoIP provider that meets PCI compliance requirements.

What Additional Measures Do They Take To Mitigate Risks?

Ask your provider what measures they take to minimize the risks associated with the VoIP threats we previously covered, including toll fraud, voicemail fraud, and DDoS attacks. For example one of the many measures net2phone takes to minimize risks, is we don’t allow usernames to be email addresses. This makes it harder for anyone to break into your account and steal your information. Choose a provider that includes additional layers of protection like this.

What Is Their Uptime Record?

VoIP uptime is the amount of time that a provider's service is operational and available to users. Uptime percentages will indicate to you the reliability of a provider's system. Look for providers with an average uptime of 99.99%.

Where Are Their Servers Located?

When you choose a provider, make sure their data centers are located within the country in which you reside. It is important to ensure that the traffic stays within your borders for data sovereignty reasons. This way, your data is not subject to external laws and regulations.

Final Thoughts: Choose Your Provider Wisely & Take Precautions

With innovative technology and robust security measures, VoIP systems are more secure than the average landline. Taking steps to mitigate risks, such as enforcing strong passwords, can minimize your organization's risk. And by choosing a provider that maintains strong security protocols, you can enjoy VoIP's many benefits with peace of mind.