The Essential Glossary of VoIP Terms (Voice Over IP)

Published by Smart Office


As businesses turn to Voice over Internet Protocol (VoIP) for communication, understanding industry terminology is crucial. VoIP offers a range of features that traditional phone systems simply can’t match, but the jargon can be overwhelming. To help you navigate our services, we’ve compiled a glossary of terms.


Whether you’re a tech-savvy professional or just starting to explore VoIP, this guide will clarify the essential concepts and ensure you’re well-equipped to make informed decisions about your communication solutions.

  • Auto Attendant: An automated system that answers incoming calls and provides a menu of options for callers to navigate. This feature can improve call management and customer service.
  • Bandwidth: The amount of data that can be transmitted over a network in a given time period. Adequate bandwidth is essential for maintaining high-quality VoIP calls and ensuring that other network activities do not interfere with communication.
  • Call Forwarding: A feature that redirects incoming calls from one number to another. In VoIP systems, call forwarding can be managed through software settings, allowing for rapid disaster response and greater flexibility for hybrid and flex workers.
  • Call Parking: A feature that allows users to place a call on hold and retrieve it from another phone within the same VoIP system, making it easier to transfer calls or handle multiple conversations.
  • Call Routing: The process of directing incoming calls to specific extensions, departments, or locations based on predetermined criteria, such as caller input or time of day.
  • Codec (Coder-Decoder): A technology that compresses and decompresses voice data for transmission over the internet. Common codecs include G.711, G.729, and G.722, each offering different balances of quality and bandwidth usage.
  • Extension: A unique number or code assigned to a specific user or department within a PBX system, allowing for internal call routing and direct dialing.
  • IP Phone: A telephone that connects directly to an IP network, allowing for VoIP communication. Unlike traditional phones, IP phones do not require a separate telephone line.
  • Jitter: Variability in packet arrival times during transmission over a network. High jitter can affect call quality by causing delays and echo. VoIP systems often use jitter buffers to mitigate its impact.
  • Latency: The time it takes for a data packet to travel from the sender to the receiver. Low latency is crucial for clear and timely communication in VoIP calls.
  • NAT (Network Address Translation): A technique used to map private IP addresses to a public IP address, allowing multiple devices on a local network to share a single public IP address. Proper NAT configuration is essential for ensuring VoIP call quality and connectivity.
  • PBX (Private Branch Exchange): A private telephone network used within an organization. VoIP-enabled PBXs, often referred to as IP-PBXs, handle internal and external communication using VoIP technology.
  • Peer-to-Peer (P2P) Communication: A type of VoIP communication where calls are made directly between users’ devices without the need for a centralized server or intermediary. This can be used in applications like Skype.
  • Quality of Service (QoS): A set of technologies and practices used to ensure that VoIP calls maintain high quality by prioritizing voice data over other types of internet traffic and managing network resources effectively.
  • SIP (Session Initiation Protocol): A signaling protocol used to initiate, maintain, and terminate voice and video calls over IP networks. SIP handles the setup and management of communication sessions.
  • SIP Trunking: A service that allows businesses to connect their PBX systems to the internet using SIP, enabling voice calls to be made and received over IP networks instead of traditional phone lines.
  • Unified Communications (UC): An integrated approach to communication that combines VoIP with other forms of communication, such as video conferencing, instant messaging, and email. UC systems streamline interactions and enhance collaboration.
  • Voicemail-to-Email: A feature that converts voicemail messages into audio files and sends them to a specified email address, allowing users to access their voicemail through their email inbox.
  • VoIP (Voice over Internet Protocol): A technology that allows voice communication to be transmitted over the internet instead of traditional telephone networks. It converts voice signals into digital data packets and sends them over the internet.
  • VoIP Gateway: A device that connects a VoIP network to traditional telephone networks or other VoIP networks. It facilitates communication between different types of communication systems.
  • VoIP Provider: A company that offers VoIP services, including call routing, voice data transmission, and often additional features like voicemail and call analytics. Examples include RingCentral, Zoom, and Vonage.

    By familiarizing yourself with these VoIP terms, you’ll be better prepared to understand the capabilities and benefits of VoIP technology. Whether you’re upgrading your business communication systems or exploring new solutions, this glossary serves as a valuable resource to help you make the most of your VoIP investment.

    Check out our other articles for more advice on specific industries and use cases.