Buyer Guide
What is VoIP? How internet calling works for business
VoIP (Voice over Internet Protocol) transmits phone calls over the internet instead of traditional phone lines. This guide covers how it works, what it means for your business phone system, and how VoIP relates to UCaaS and CCaaS platforms.
What is VoIP?
VoIP (Voice over Internet Protocol) is the technology that transmits voice calls as data packets over the internet rather than over traditional circuit-switched telephone lines. When you make a VoIP call, your voice is converted into digital data, transmitted to the recipient, and reassembled into audio — all in real time.
How it works technically: your voice is sampled and digitized by a codec (common choices: G.711 for high quality, G.722 for wideband HD voice, G.729 for compressed low-bandwidth). The codec packages the digital audio into IP packets. Those packets travel over your internet connection to the provider's infrastructure, encrypted using TLS for call signaling and SRTP for the media stream, then delivered to the recipient's device where they're decoded back into audio.
VoIP vs traditional phone systems
| Aspect | Traditional Phone (PSTN) | VoIP |
|---|---|---|
| Infrastructure | PBX hardware, PSTN lines | Internet connection, cloud or hosted PBX |
| Cost model | High capex, per-minute PSTN | Monthly subscription or SIP trunk |
| Remote work | Physical location tied | Any internet-connected device |
| Number portability | Limited | Number porting supported |
| Scalability | Hardware purchase required | Add users in admin console |
| International calls | High per-minute rates | Lower rates via internet routing |
What affects VoIP call quality
VoIP call quality is driven by network characteristics rather than raw bandwidth. A 10 Mbps connection with poor jitter will sound worse than a 5 Mbps connection with low jitter.
Jitter
Variation in packet arrival time. High jitter causes choppy or robotic audio. Mitigated by QoS rules that prioritize voice packets.
Latency
Delay between speaking and the recipient hearing you. Acceptable one-way latency for voice is under 150ms. Over 200ms causes noticeable conversation lag.
Packet loss
Packets that never arrive. Even 1–2% packet loss produces audible gaps. A wired connection and QoS configuration reduce packet loss significantly.
Codec selection
G.711 provides higher quality at ~64 Kbps. G.722 wideband improves clarity. G.729 compresses to ~8 Kbps for low-bandwidth environments.
Best practice: use a wired connection for office VoIP deployments and configure QoS rules to prioritize voice packets on shared networks.
VoIP vs UCaaS: what's the difference?
VoIP is the transport technology. UCaaS is a complete communication platform built on top of VoIP — it adds video meetings, team messaging, presence, softphone apps, admin console, and integration APIs. Every UCaaS platform uses VoIP for its calling layer, but a standalone VoIP service doesn't include video, messaging, or the management layer UCaaS provides.
If you need phone calls only, a standalone VoIP or SIP trunking service may be sufficient. If you need phone, video, messaging, and collaboration in one platform, UCaaS is the right category. See What is UCaaS? and VoIP vs UCaaS (blog article) for a full comparison.
Business VoIP use cases
Small business replacing PBX
Eliminate on-site hardware and IT maintenance. A hosted VoIP or UCaaS subscription covers all extensions without capital expense.
Remote and distributed teams
VoIP numbers work from any internet-connected device. Remote employees use the same business numbers as office staff.
Contact center inbound/outbound
CCaaS platforms are built on VoIP infrastructure — inbound queues and outbound campaign dialers all run over the internet.
International calling
VoIP routes international calls over the internet rather than PSTN, typically at significantly lower per-minute rates.
Related Guides
Continue reading
FAQ
Frequently asked questions
What does VoIP stand for?
VoIP stands for Voice over Internet Protocol. It is the technology that transmits voice calls as data packets over the internet rather than over traditional circuit-switched telephone lines.
How does VoIP work?
When you speak into a VoIP phone or softphone, your voice is sampled and converted into digital data packets. Those packets travel over the internet to the recipient — encrypted in transit — where they are reassembled and converted back into audio. The conversion process is managed by a codec; common business VoIP codecs include G.711 and G.722.
Is VoIP reliable for business use?
Modern business VoIP is reliable for the majority of businesses on a stable broadband connection. Call quality depends more on network jitter, latency, and packet loss than raw bandwidth. Businesses with high call volumes often configure a dedicated VLAN or QoS (Quality of Service) rules to prioritize voice traffic.
What is the difference between VoIP and UCaaS?
VoIP is the underlying technology for transmitting voice calls over the internet. UCaaS is a complete cloud communication platform that uses VoIP for its calling layer and adds video meetings, team messaging, presence, and collaboration tools. All UCaaS platforms use VoIP; not all VoIP services are UCaaS.
What equipment do you need for business VoIP?
A stable internet connection and a softphone application (desktop or mobile) are sufficient. Physical IP phones are optional — most businesses use softphone apps on laptops and smartphones. A VoIP adapter (ATA) can connect analog phones if needed.
How does VoIP pricing compare to traditional phone systems?
VoIP eliminates the hardware cost of a PBX and the per-minute charges of traditional PSTN calling for most domestic calls. Businesses pay a monthly subscription per user (for hosted VoIP/UCaaS) or SIP trunk fees (for premise-based VoIP). International calling costs vary by provider and destination.
Business phone built on enterprise VoIP infrastructure
EaseDial delivers cloud calling, video, messaging, and contact center on a reliable VoIP platform — no hardware, no PBX to maintain.