Glossary · VoIP
What is VoIP?
VoIP (Voice over Internet Protocol) is a technology that transmits voice calls as digital packets over an IP network — the internet or a private network — instead of the traditional analog Public Switched Telephone Network (PSTN). VoIP lets users make and receive calls from computers, smartphones, desk phones, or software apps without a dedicated analog phone line. It dramatically reduces long-distance costs, unlocks features that are expensive or impossible on legacy systems, and is the foundation of all modern cloud phone services.
How VoIP works
- Your voice gets digitized and compressed by a codec (G.722, Opus, G.711)
- The audio stream splits into small data packets
- Packets travel over IP networks to the recipient
- At the recipient’s end, packets reassemble and decompress
- Audio plays to the recipient’s speaker or headset
The whole round trip typically completes in under 100 milliseconds — fast enough to feel like a real-time conversation.
Why businesses use VoIP
- Lower cost — long-distance and international calls run at a fraction of PSTN rates
- No dedicated lines required — calls go over your existing internet connection
- Feature richness — auto attendant, voicemail transcription, call recording, video meetings, SMS all integrated
- Mobility — the same business number rings your desk, laptop, and phone
- Integration — native connection to CRMs, helpdesks, calendars
- Easy scaling — add a user in minutes, not weeks
- Remote-work ready — works anywhere with internet
VoIP vs. landline
| Dimension | Landline (PSTN) | VoIP |
|---|---|---|
| Infrastructure | Dedicated phone lines | Existing internet connection |
| Cost per line | $30–$75/month | $24–$54/user/mo (DialPhone) for full feature set |
| Long-distance | Expensive per-minute | Often unlimited within region |
| Mobility | Tied to physical line | Works from any device, anywhere |
| Features | Basic calling | Full suite: SMS, video, AI, recording |
| Reliability | Survives power outages (copper) | Depends on internet + power |
| Emergency calling (911) | Works natively | Requires E911 configuration |
VoIP call quality considerations
VoIP quality depends on network conditions:
- Bandwidth — 100 Kbps per concurrent call is the minimum; 150+ Kbps for HD
- Latency — under 150ms one-way is ideal; 300ms+ becomes noticeable
- Packet loss — under 1% is acceptable; over 3% becomes disruptive
- Jitter — variation in packet arrival time; jitter buffers smooth small variations
Enterprise-grade VoIP providers (like DialPhone) use carrier-grade routing, global edge points, and intelligent codec selection to maintain call quality on ordinary broadband. Most customers on a reasonable internet connection get HD quality without touching network configuration.
VoIP deployment models
- Hosted VoIP / UCaaS — the provider hosts everything in the cloud (most common today)
- SIP trunking — provider delivers dial tone via SIP trunking; customer runs their own PBX
- On-premises VoIP — customer runs a VoIP-capable PBX and handles all infrastructure
DialPhone is a hosted VoIP platform with AI features layered on top. You sign up, port your number, download apps, and start calling. No hardware. No PBX to manage.
VoIP and compliance
VoIP calls can be recorded, encrypted, and archived to meet compliance requirements including:
- HIPAA — healthcare-related calls with Business Associate Agreements
- FINRA — financial services call recording and retention
- PCI-DSS — payment-over-phone call handling
- GDPR — EU data residency and consent tracking
- TCPA — outbound dialing compliance (see TCPA)
Enterprise VoIP providers build these compliance layers into the platform. See the DialPhone trust center →
Example
A 30-person law firm replaced a 15-year-old Avaya PBX with DialPhone VoIP. Savings: $2,100 per month on eliminated phone lines and PBX maintenance. Added capabilities: mobile apps for field work, AI call transcription for matter documentation, business SMS for client intake, HIPAA-compliant fax for medical records referrals. Setup took 4 hours across 30 users with their numbers ported in 3 business days.
See VoIP in action
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