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.
What is non-fixed VoIP?
Non-fixed VoIP is a VoIP number that is not tied to a physical street address. Anyone with an email and internet connection can register one in minutes, often from anywhere in the world. Services like Google Voice, Skype, and most cloud business phone platforms issue non-fixed VoIP numbers by default. Fixed VoIP, by contrast, is provisioned against a verified service address — the way a traditional landline is — and is required for E911 dispatch and many regulated workflows. Non-fixed VoIP trades that location-binding for portability, instant provisioning, and lower cost.
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
AI business phone system (VoIP) → · Small business VoIP → · Compare VoIP providers → · Business VoIP complete guide 2026 →
VoIP service pricing in 2026
Headline VoIP prices look similar across providers. What you actually pay over three years usually does not. Here are published per-seat list prices for the top platforms, billed annually:
| Provider | Entry tier | Mid tier | Top tier |
|---|---|---|---|
| DialPhone | Core $24 | AI Pro $34 | Enterprise $54 |
| RingCentral | Core $20 | Advanced $25 | Ultra $35 |
| Nextiva | Essential $18.95 | Professional $22.95 | Enterprise $32.95 |
| Dialpad | Standard $15 | Pro $25 | Enterprise custom |
| 8x8 | X2 $24 | X4 $44 | X6 $85 |
All prices are per user per month on annual contracts. Month-to-month billing usually adds 25-40%. Multi-year contracts (2 or 3 years prepaid) can shave another 10-15% off but lock you in. Mid-market and enterprise buyers should expect 15-30% discounts off list with a proper procurement cycle; SMB list prices are mostly take-it-or-leave-it unless you bring 20+ seats.
The list price is not the bill. Real costs that show up later:
- Number porting: some providers charge $25-$200 per number to port your existing DIDs in or out. Read the port-out clause before you sign.
- AI add-ons: RingCentral charges roughly $25/user/month for advanced AI on top of the base seat. DialPhone bundles AI into the AI Pro tier at $34.
- International calling: most “unlimited” plans cover US and Canada only. International minutes are billed per-minute or sold as a separate bundle.
- Recording storage caps: many entry tiers cap recording retention at 30-90 days. Pulling unlimited or compliance-grade retention often forces a tier upgrade.
- Toll-free numbers: usually one included; additional toll-free DIDs run $5-$15/month each plus per-minute inbound charges.
- Premium support: 24/7 SLAs and dedicated CSMs are often gated to top tiers.
Published list price is the starting line. Total cost of ownership across three years, including add-ons, porting, overage, and the price of the tier upgrade you will eventually need, is what to compare. See full DialPhone pricing →
What “VoIP phone service” actually includes in 2026
For $20-$30 per seat in 2026, a buyer should expect every one of these as standard:
- Unlimited inbound and outbound calling in the US and Canada
- Business SMS and MMS from your business number
- Mobile apps (iOS, Android) and desktop apps (Mac, Windows)
- Auto attendant and IVR menus
- Voicemail-to-email with transcription
- Call recording (usually with a 30-90 day retention cap on entry tiers)
- Basic integrations with Google Workspace, Microsoft 365, and mainstream CRMs (HubSpot, Salesforce, Pipedrive)
- HD video meetings for small teams
- Online fax with a fax number
- Call logs, basic analytics, and a shared inbox view
These features are table stakes. If a provider gates any of them behind an upgrade, that is a pricing signal, not a product limit. A common bait-and-switch pattern: list price quoted on the entry tier, but features any business actually needs (call recording, basic CRM integration, voicemail transcription) only ship on the middle tier 30-50% more expensive. Confirm feature parity to your shortlist before comparing prices.
What typically costs extra, even at the top tier:
- AI features: live transcription, call summarization, agent assist, conversational analytics
- Advanced analytics: custom dashboards, queue-level KPIs, supervisor real-time views
- Contact center modules: skills-based routing, workforce management, omnichannel
- International calling: anything outside US and Canada is per-minute or a paid bundle
- Additional toll-free numbers: first one free, the rest billed monthly + per-minute
- Premium support SLAs: 24/7 phone support, named CSMs, dedicated migration help
- Compliance: HIPAA BAA, FINRA archive integrations, SOC 2 reports sometimes on Enterprise only
- Additional E911 locations: each registered emergency dispatch address may carry a small monthly fee on multi-site deployments
- Vanity and international DIDs: memorable vanity numbers and non-US local DIDs usually carry one-time setup fees and higher monthly rentals
If a sales rep says everything is included, get it in writing in the order form, not the website.
How to choose a VoIP provider
Seven things to evaluate before signing a contract:
- Three-year total cost, not headline price. Build a spreadsheet with base seats, add-ons you will use, expected number of additional DIDs, recording storage, and international minutes. The cheapest list price often becomes the most expensive bill by year two.
- SLA-backed uptime. Look for a written 99.999% SLA with service credits, not a marketing “99.9%” that translates to 8.7 hours of downtime per year. Five-nines is 5.26 minutes per year.
- Number portability terms. Confirm port-in is free and port-out has no punitive fee or hostage clauses. Some providers charge $25-$200 per number to release on cancellation.
- Mobile app quality. Download the iOS and Android apps before signing. Check App Store ratings in the last 90 days, not lifetime. Test a call, an SMS, and a transfer.
- Integration depth with your CRM. “Integration” can mean a click-to-call browser extension, or full activity sync with screen pop and post-call logging. Demand a live demo with your actual CRM.
- AI roadmap. Real-time transcription, call summarization, and agent assist are now standard on serious platforms. If a provider charges $25/user/month extra for AI, factor it into the comparison.
- Compliance posture. If you handle PHI, signed financial advice, or EU data, confirm in writing: HIPAA BAA available, FINRA 17a-4 retention supported, GDPR data residency options, SOC 2 Type II report current. See DialPhone trust center →
Bonus checks that catch real problems: ask for a reference customer in your industry at your headcount, request a 14-day trial with live porting on a test number, and read the auto-renewal clause. Many VoIP contracts auto-renew for a full year unless you cancel 60-90 days out, which traps buyers who only discover the clause when they try to switch.
VoIP for industry use cases
VoIP capabilities matter differently by vertical. A 30-person law firm and a 30-person ecommerce support team buy on completely different criteria, even at the same headcount and price band. The features that move the contract for one are noise for the other. A few common verticals:
- Healthcare — VoIP for healthcare — HIPAA BAA, encrypted call audio, voicemail transcription routed to EHR, and recording with retention controls. Patient privacy and BAA coverage are the gating requirements.
- Legal — VoIP for legal — call recording for matter documentation, conflict-check-friendly call logs, and AI transcription that produces billable-time-grade records. Look for matter-level tagging.
- Real estate — VoIP for real estate — mobile-first apps for agents in the field, easy porting of legacy office numbers, and SMS for buyer outreach. Number portability is non-negotiable.
- Financial services — VoIP for financial services — FINRA 17a-4 compliant recording retention, write-once archive integrations, and PCI-friendly call flows for payment capture.
- Ecommerce — VoIP for ecommerce — CRM and helpdesk integrations (Shopify, Zendesk, Gorgias), shared inbox for support, and 24/7 toll-free routing.
VoIP frequently asked questions
Is VoIP cheaper than a landline?
Yes, for almost any business with more than two lines. A traditional landline runs $30-$75 per line per month plus per-minute long distance and feature add-ons. VoIP plans bundle unlimited US and Canada calling, voicemail, SMS, video, and mobile apps into $18-$35 per user per month. A 10-person business typically cuts phone spend by 50-70% in year one, and saves more in year two by retiring on-premises PBX hardware and maintenance contracts. Total savings depend on call volume and existing infrastructure.
Do I need new phones to switch to VoIP?
No. Most VoIP providers ship a desktop app and a mobile app on day one, which is what 80%+ of business users actually use. If you want physical desk phones, any SIP-compliant IP phone works (Yealink, Poly, Cisco), and you can usually reuse existing IP phones from a previous provider after a firmware reset. Analog desk phones from a landline era will not work directly, but a $40-$80 ATA (analog telephone adapter) converts them to SIP. Most teams skip desk phones entirely.
What internet speed do I need for VoIP?
Plan on 100 Kbps per concurrent call as a hard minimum, and 150-200 Kbps per call for HD audio. A 10-person office with five simultaneous calls needs roughly 1 Mbps reserved for voice, well within any modern broadband connection. Latency under 150ms one-way and packet loss under 1% matter more than raw bandwidth. A 100 Mbps fiber connection with QoS configured will handle 50+ concurrent calls without quality issues. If you are on shared Wi-Fi with heavy video traffic, prioritize voice with QoS rules.
Can I keep my existing phone number with VoIP?
Yes. Number portability is a regulated right in the US and most countries. The process, called number porting, typically takes 3-10 business days for local numbers and 2-4 weeks for toll-free. Your new VoIP provider files an LOA (Letter of Authorization) and submits the port request to your old carrier. There is no service interruption when done correctly. Some providers charge $25-$200 per port-out fee if you ever leave; ask before signing. Port-in is almost always free with reputable providers.
Is VoIP secure for business calls?
Modern VoIP is at least as secure as a landline, often more so. Reputable providers encrypt voice traffic with SRTP and signaling with TLS 1.2 or higher. Look for SOC 2 Type II compliance, optional end-to-end encryption for sensitive calls, single sign-on (SSO) with SAML or OIDC, and role-based admin controls. Risks are real but manageable: weak account passwords, SIP toll fraud on misconfigured PBXs, and social engineering. Enterprise providers add fraud monitoring, IP allowlisting, and 24/7 SOC coverage. Avoid free or unverified VoIP services for business use.
Does VoIP work if the power goes out?
Not directly. VoIP needs both power and internet. Traditional copper landlines draw power from the central office and survive local outages, which is one of the few remaining advantages of PSTN.
Mitigations: a $100-$300 UPS keeps your router, switch, and any desk phones running for 30-60 minutes; mobile VoIP apps continue working on your phone’s cellular data; configure call forwarding to a mobile number as an automatic failover. Enterprise deployments often pair VoIP with 4G/5G failover routers for sub-minute restoration. For 911 access during outages, mobile phones remain the safest fallback.
Related guides
- VoIP vs. landline: the 2026 comparison
- How to choose a business phone system
- VoIP pricing guide 2026
- PBX — the on-premises predecessor to VoIP
- SIP trunking — how enterprises connect existing PBX to VoIP
- DialPhone business phone pricing