What is IP Telephony?
IP telephony (Internet Protocol telephony) is a term used to describe technologies that use a variety of protocols to exchange voice, fax, and other forms of information, traditionally carried over the Public Switched Telephone Network (PSTN). The call travels in the form of packets, over a Local Area Network (LAN), or the Internet, avoiding PSTN tolls.
Starting in the mid to late 1990s, the Internet and the TCP/IP protocol began to drive the telephone and communications industry to change. The Internet Protocol became the transport for almost all data communications. Today, all communication carriers are using an IP infrastructure for a part, or for all of their voice services. Most companies have already switched from PSTN to using VoIP (Voice over IP) for their internal voice communications or have plans to implement it as part of their Unified Communications solution.

What are VoIP protocols?
Several core protocols power IP telephony:
IP telephony in business
The benefits of IP telephony in corporate environments are numerous, but are mostly narrowed down to cost considerations related to infrastructure and monthly telco bills. Modern VoIP PBX solutions, like 3CX, allow for companies to run the system on existing, non-proprietary hardware as well as low-cost machines such as Mini-PCs. Traditional phone systems and proprietary VoIP systems require extensive implementation of closed architectures, which can cost hundreds of thousands of dollars and are much more difficult to manage, configure and maintain. Open standards IP telephony systems are also much easier and more cost-effective to scale.
The use of VoIP phone systems and VoIP service providers means that phone bills are greatly reduced. This is because companies can easily connect branches in other cities and countries, making phone calls within the company free. Long-distance charges are slashed and overall call rates are much cheaper.
A comprehensive contact center
Business telephone systems are now able to offer much more to companies than standard telephone calls. IP telephony services have ushered in the development of unified communications solutions which can provide a complete communications package all in one, to be run over a single network and on one platform. This means that businesses can easily manage calls, and collaborate using video conferencing and instant messaging in one system. These solutions have also allowed users to make VoIP telephone calls through their smartphones and computers, either with the use of apps or web clients.
Here is what you can expect from an all-in-one business phone system:
- Unified Communications: Integrating video, voice, chat, and email.
- VoIP Calling: Cost-efficient IP network calls.
- Call Queues & Routing: Automatic call distribution (ACD), skill-based routing, and ring groups.
- Video Conferencing: Secure, high-quality meetings with no additional cost.
- Mobile App: Allows users to manage calls and messages from anywhere.
- CRM Integration: Sync with popular CRM tools for better customer service.
- Call Recording & Monitoring: For quality assurance and training.
Enhance your business communication with 3CX’s unified phone system that integrates voice, video, and chat into one powerful platform. Reduce costs with VoIP calling and optimize productivity with advanced features like call queues, CRM integration, and mobile access. Take control of your communication today with 3CX and empower your team to work smarter from anywhere.
Your questions answered…
Further reading
Last Updated
This document was last updated on 4 July 2025
https://www.3cx.com/pbx/what-is-ip-telephony/

