Importance of Firewall in VoIP Phone System

November 1, 2021by Russell0
Importance of Firewall in VoIP Phone System

Everything that is online needs security to stay safe from cyber security. A firewall is the first line of defense for any online system.

Execution of a cyber attack can damage the entire system, which may subsequently lead to damage to the VoIP system as well. Integral security like a firewall is needed to protect only the VoIP but also the overall infrastructure.

What is VoIP Firewall?

The term VoIP firewall comes from the architecture of old townhomes. You will probably notice a thick wall separating each unit. This wall is known as the firewall. This is used to provide protection against fire.

— Similarly in a PBX network, a VoIP firewall is used to control and monitor the transaction between IP packets within a truncated internal network or an untrusted external network.

The Importance of Using Firewall in VoIP Phone System

To know the importance of using a firewall in a VoIP phone system, you need to the consequences of cyberattacks. Most people find the term ‘hack’ or “cyber-attack” very abstract. They don’t know how this type of incident occurs or what are the consequences.

Let’s get to know the importance of using a firewall in VoIP networks,

  • Hackers may use impersonate attacks to commit toll fraud. In case you don’t know, toll fraud is the use of an illegally obtained telephone access code to make long-distance calls. As a result, hackers may use your VoIP system to make long-distance fake calls when you are the one who is paying.
  • That’s not all, hackers or cyber criminals may expose sensitive information or may exploit security vulnerabilities of your system by capturing voice conversations.
  • Aside from that, some may try to flood the VoIP network with SIP call-signaling messages. They may perform Distributed Denial of Service or DDoS attacks to lower the quality of communications or break it down entirely.
  • To prevent these types of threats from potential attackers, unauthorized connections get blocked by the firewall from entering the router. A firewall is the security mechanism that filters both incoming and outgoing traffic in internal or external networks.
  • Did you know?

-Most cyberattacks target the end-points of the network. 

cyberattacks target

Thus, if a VoIP firewall is connected in front of end-point devices such as handsets and computers running on softphones, the security threat will be greatly reduced.

  • Furthermore, unwanted traffic may try to enter into the internal network by accessing other applications. A firewall helps the network administrators to hide devices from port scans to ignore unsolicited network traffic.
  • Many times, key-loggers, malware, or various viruses enter the internal infrastructure and carry out criminal activities. Firewalls protect the internal infrastructure by reducing their spread. Firewalls also monitor outbound connections to prevent malware from leaking confidential information.

— Firewalls can be a key component of the VoIP network security architecture when configured correctly. This will give your VoIP network maximum security as well as privacy.

Required Hardware and Software of VoIP Firewall

VoIP firewalls are available in two forms – hardware and software. There is also a third type of form, which is the combination of both software and hardware. With secure authentication and logins, a firewall increases the security to access one’s network and computer.

Hardware Firewall

This type of firewall can either be included in broadband routers or as stand-alone products. While setting up a network, the hardware firewall plays an important role in the security infrastructure. To connect to other computers, a hardware firewall contains a minimum of 4 ports. However, it is better to go for advanced firewall solutions when your business is large.

Software Firewall

Unlike the hardware form, installing and configuring the software form of firewall is easy. The process is the same as installing any other software. The configuration of the software firewall is also easy.

The software firewall prevents external attempts to gain access to computers or networks. A software firewall allows the users to control its functions and protection features.

Functions of VoIP Firewall

The VoIP firewall mainly filters information from the transaction between a computer and a private network over a reliable internet connection. Some important functions of the VoIP firewall are –

  • Act as a mediator between a computer and a network.
  • It records events and provides reports in accordance with the event.
  • It controls and manages network traffic.
  • Implement validation for authorization.
  • It helps to validate resources.

The Filtering Technique of VoIP Firewall

Whether it is your home or corporate network, a firewall protects both by preventing potentially harmful acts.

Related Next: Best Wholesale VoIP Softswitch

Here is the overview of the filtering technique of the VoIP firewall –

  • Packet filter:

VoIP firewall examines each and every packet while entering and leaving the network. The users define the rule for packet rejection. The configuration of packet filtering is not an easy task. It is considered IP spoofing most of the time.

  • Application gateway:

This type of security measure is needed to specify specific applications such as Telnet and FTP servers. Although the application gateway is very effective, it can occur performance degradation.

  • Circuit level gateway:

When you establish a connection between a TCP and UDP, this type of security mechanism is needed. Once the connection is established, the packets start to pass through hosts without further verification.

  • Proxy server:

The proxy server is responsible for intercepting all types of messages that enter and leave the network.

The Best Firewall Practice: SBC and VoIP Firewall

The best practice for implementing a unified communication system is to use both a VoIP firewall and an SBC. This is because they complement and support each other in a common function.

Both SBC and VoIP firewalls perform the same type of network border security, but their types of work are different. Traffic on a network is standardized in the OSI model. This is the structure or hardware of the network where traffic is abstracted at seven levels but does not know how it arises.

This type of standardization provides evidence for the presence of large networks across different systems, such as the Internet.


You don’t want any information about your VoIP business to fall into wrong hands. Any information, especially the private ones is too valuable. It preserves your business privacy. And there you will need a VoIP firewall. Consider the VoIP firewall as the first line of defense in your entire security infrastructure.

—As a result, a VoIP firewall can save your business from losses and help you to avoid any security breaches.


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OUR LOCATIONSWhere to find us?
Stay up to date with the latest news about VPSVOS Communication, events, special offers and more by connecting with our social media.

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