For many decades, voice communications and network traffic were completely separate entities. Analog networks carried voice traffic while digital networks carried data. Times have changed however, and these networks have converged. Learn the security issues around the use of telephony on a network.
- [Narrator] For many decades, voice communications and network traffic were completely separate entities. Analog networks carried voice traffic, while digital networks carried data. Times have changed, however, and these networks have converged. Voice over Internet Protocol, or VoIP technology, now allows the use of a single data network for both voice and data communications. VoIP works by converting voice signals from analog to digital form, and then simply tranmitting them using the same IP protocol that carries other network communications.
Users of VoIP technology may use a variety of different devices to communicate. These range from dedicated VoIP phones that look like regular telephones but connect directly to a data network, to soft phones that are simply software running on a computer or mobile device, or hardware used to bridge an existing analog telephone network to a digital network for communication over the internet. The use of VoIP technology does introduce some security issues that administrators must be aware of as they design voice networks, encryption and network segmentation.
Both of these technologies are designed to prevent unauthorized use of VoIP networks and unauthorized eavesdropping on authorized communications. As in many eavesdropping attacks, encryption is one of the best ways that you can protect voice communications. Encryption scrambles the content of telephone calls, and prevents eavesdroppers from listening in on those communications. Unfortunately, encryption is not always viable on voice networks, due to the cost and functionality loss that encryption adds. In many cases, the use of encryption noticeably distorts the voice of telephone users to an extent that those users find unacceptable.
When encryption isn't viable, VoIP administrators may achieve some protection against eavesdropping through the use of a separate VLAN for voice communications. They may use network access control, NAC technology, to prevent any device other than a VoIP phone from connecting to the voice VLAN. This prevents attackers from connecting a traditional computer to the network, and then using a protocol analyzer, such as Wireshark, to eavesdrop on voice communications. VoIP administrators must implement controls to protect the security of telephone communications carried over data networks.
Learn about communication and networking best practices, including TCP/IP networking, network security devices, and secure network design and management. Instructor and cybersecurity expert Mike Chapple also includes coverage of converged protocols, network encryption, and wireless networking. You can find Mike's companion study books for this series at the Sybex test prep site and review the complete CISSP Body of Knowledge at https://www.isc2.org/cissp-domains/default.aspx.
- IP addressing
- Switches and routers
- Content distribution networks
- Designing secure networks
- Specialized networking
- Managing secure networks
- Working with virtualized networks like SDNs
- Detecting and preventing network attaches
- Transport encryption
- Wireless networking
- Host security
Skill Level Advanced
CISSP Cert Prep: 2 Asset Securitywith Mike Chapple58m 11s Advanced
1. TCP/IP Networking
2. Network Security Devices
3. Designing Secure Networks
4. Specialized Networking
5. Secure Network Management
6. Virtualized Networks
Port isolation1m 47s
7. Network Attacks
8. Transport Encryption
9. Wireless Networking
10. Host Security
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