Thirteen methods to Ensure VoIP network security

VoIP refers to voice transmission over a network that uses the Internet Protocol. The IP address represents the Internet Protocol and is the hub of the Internet, internet protocols can transmit emails, instant messages, and webpages to thousands of PCs or mobile phones. Some people say it is the killer of telecommunications, and some say it is a revolutionary factor in international affairs. In a word, it is widely praised. However, when you use this service, a hacker may steal your personal information or even destroy your network.

All attacks that affect the data network may affect the VoIP network, such as viruses, spam, illegal intrusions, DoS, phone hijacking, eavesdropping, and data sniffing. The only difference is that we are more willing to take some measures to protect other networks. There are few specific measures for VoIP. In fact, this technology is only possible for us to take some protective measures.

The following describes how to protect VoIP:

1. restrict all VoIP data to only one VLAN

Cisco recommends dividing VLANs for voice and data separately to help process voice and data in priority. VLAN Division also helps defend against fraud, DoS attacks, eavesdropping, hijacking, and communication. VLAN Division allows a user's computer to form an effective closed circle. It does not allow any other computer to access its devices, thus avoiding computer attacks and making the VoIP network quite secure; even if you are attacked, the loss will be minimized.

2. monitor and track the communication modes of the VoIP network

Monitoring tools and intrusion detection systems can help users identify attempts to intrude into the VoIP network. Observing the VoIP logs in detail can help you find out some irregular things, such as inexplicable international phone numbers, international phone numbers that are basically not in contact with the company or organization, attempts to crack passwords and surge in voice.

3. Protect VoIP servers

Effective measures must be taken to ensure the security of the server to prevent internal or external intruders from intercepting data using sniffing technology. Because VoIP phones have fixed IP addresses and MAC addresses, attackers can easily intrude into the phones. We recommend that you restrict IP addresses and MAC addresses, do not allow random access to the Super User Interface of the VoIP system, and create another firewall before the SIP gateway, in this way, network system intrusion will be limited to a certain extent.

4. Use multiple Encryption

Encryption of sent data packets alone is far from enough. All telephone signals must be encrypted. Conversational audio encryption prevents the interceptor's speech from being inserted into the user session. In this regard, the SRTP protocol can encrypt the end point communication, and TLS can encrypt the entire communication process. Audio Transmission encryption should be supported by providing powerful protection at the gateway, network, and host layers.

5. Establish a redundancy mechanism for the VoIP network

Always be prepared to be vulnerable to viruses and DoS attacks, which may paralyze the network system. Build a network system that can set up multi-layer nodes, gateways, servers, power supplies, and call routers, and connect with more than one supplier. It regularly tests various network systems to ensure they work well. When the main service network is paralyzed, the standby facilities can quickly take over the work.

6. Place the device behind the firewall

Establish a separate firewall so that communication through VLAN boundaries is limited to available protocols.

In case the client is infected, this will prevent viruses and trojans from spreading to the server. After a separate firewall is established, the maintenance of system security policies becomes simple. When necessary, you must correctly configure the firewall to enable or disable some ports.

7. Regularly update Patches

The security of the VoIP network depends on both the underlying operating system and the application software running on it. Keeping the operating system and VoIP application software patches updated in a timely manner is very important to defend against malicious or infectious program code.

8. Separate the internal network from the Internet

Putting a telephone management system and a network system out of direct access to the Internet is a good choice. It places the voice service and other servers in a separate domain and restricts access to it.

9. Minimize the use of softphone

VoIP soft terminal phones are vulnerable to computer hacking, even after the company's firewall, because they are used together with common PCs, VoIP software, and a pair of headphones. Moreover, soft terminal phones do not separate voice and data, so they are vulnerable to viruses and worms.

10. Conduct regular security reviews

You can check the activity of Super Users and general users to find some problems. Some "phishing" attempts can be blocked, junk information can be filtered, And intruders can also be blocked.

11. Evaluate the actual security

Ensure that only authenticated devices and users can access the limited Ethernet ports. The Administrator is often spoofed to receive requests that are not allowed by the soft terminal phone, because hackers can easily mimic the IP address and MAC address by inserting the listen 44 port.

12. Merchants providing digital security certificates

If the IP phone provider can provide a certificate to authenticate the device, the user can basically make sure that the communication is secure and will not broadcast to other devices.

13. ensure the security of the Gateway

You need to configure a gateway so that only authorized users can make or receive VoIP calls and list the authenticated and approved users. This ensures that no one else can make a free call. The combination of SPI firewall, Application Layer Gateway, network address translation tool, and SIP support for VoIP soft clients can protect the gateway and the LAN located behind it.

1. Protecting VoIP Security in multiple layers
2. Layer-based VoIP Security