20 Best VoIP phone systems and integrations
Explore the top 20 VoIP phone systems for 2025, focusing on features, pricing, and integration benefits to enhance business communication. Discover how to selec...


SIP calling (Session Initiation Protocol) is a signaling protocol for managing communication sessions over VoIP and cloud platforms, favored for cost efficiency, scalability, and flexibility in supporting voice, video, and multimedia communications.
SIP calling is also known as Session Initiation Protocol calling. Session Initiation Protocol is a signaling protocol used for initiating, maintaining and terminating communication sessions over VoIP and other Internet and cloud-based communication platforms. SIP calling is often interchanged with VoIP calling, however, that isn't exactly correct.
VoIP (Voice over Internet Protocol) is a broader term that refers to a group of technologies used for sending and receiving phone calls made over the internet rather than traditional phone lines. While SIP is one individual technology that supports VoIP. In addition to voice calls, SIP protocol is used to transmit various data, including video chats and video calls, video conferencing, instant messaging and other multimedia communications.
Apart from initiating telephone calls, a SIP phone system is capable of performing other VoIP functions, such as identifying user location, determining their availability to respond and whether the recipient’s device is compatible with the initiated call type, transferring and terminating calls, etc.
A traditional phone system consists of three core parts:
SIP calling basically allows omitting PRI lines as it uses a SIP trunk (which is a virtual connection) that directly connects PBX with PSTN over the Internet. SIP calling also removes the need for multiple phone lines which allows for easier and cheaper scalability as compared to using traditional business phone lines.

Since each SIP trunk can hold an unlimited number of channels (a channel is equivalent to one incoming or outgoing call), a business would require a single SIP trunk regardless of the number of concurrent calls. Instead of purchasing additional phone lines that usually come in clusters of 23 (which is typically more than actually used), with SIP calling you can buy one channel at a time only when it’s needed.
Besides, SIP calling provides significant cost-savings in business communications as local, long-distance and international calls can be made by simply using the internet connection.
SIP calling and LiveAgent helpdesk software are two products that can be seamlessly integrated, providing business owners with a unified communication experience for their customers. This integration allows customers to place calls directly to the helpdesk and for helpdesk agents to easily access customer information and knowledge bases.
With SIP calling, businesses can save time and money by making calls more efficient, and LiveAgent helpdesk software ensures customer service is always at the highest level.
Make cost-efficient VoIP calls with LiveAgent's SIP trunking provider integrations including Twilio, with call recording and robust tracking.
Explore the top 20 VoIP phone systems for 2025, focusing on features, pricing, and integration benefits to enhance business communication. Discover how to selec...

Sinch offers global VoIP solutions, including voice, video, SMS, and API integration for diverse industries. Easily integrate Sinch with LiveAgent to manage mul...

Discover the benefits of VoIP PBX, a flexible, cost-effective phone system for businesses offering scalability, mobility, and data security.