Your call quality is only as good as your internet connection.
Bandwidth, latency, jitter, and packet loss each affect VoIP and video calls in a different way. See what “good enough” actually looks like, test your own connection, and find out what it would take to fix it.
Live example connection
Download 41 Mbps
Upload 6 Mbps
Latency 38 ms
Jitter 47 ms
A call quality problem can start at any point along the way
Most people blame the Wi-Fi first. Sometimes that’s right — but the one link most businesses can actually upgrade is the connection between their building and the internet.
Your device
Headset, laptop, or desk phone. CPU load and old hardware can add their own delay.
→ Router & Wi-Fi
Congested wireless channels or an outdated router add jitter before traffic even leaves the building.
→ Your internet connection
DIA vs. broadband, upload capacity, and how many other things share the line. This is what this page is about.
→ The public internet
Routing between your ISP and the other party. Outside your control, but a Tier 1 carrier helps.
→ The other end
The person you’re calling has this exact same chain on their side.
The five things that determine call quality
Every VoIP or video call is a stream of small data packets that has to arrive complete, in order, and on time. These are the measurements that decide whether it does.
Download speed
How fast data can reach you — the other person’s voice and video, screen shares, and anything else arriving on the call.
Too low: frozen video, audio that drops out or arrives in bursts.
0, 1.5 Mbps, 3 Mbps, 10 Mbps+
Upload speed
How fast data leaves your building — your voice, your video, your side of the screen share. Most home and small-office broadband plans are heavily lopsided toward download, which makes upload the first thing to run out.
Too low: you sound fine to yourself, but others can’t hear or see you clearly.
0, 1.5 Mbps, 3 Mbps, 10 Mbps+
Latency
The round-trip time for a packet to reach the other person and back, measured in milliseconds. Distance, congestion, and how many hops the data takes all add to it.
Too high: noticeable delay, people talking over each other, awkward pauses.
0ms, 150ms, 250ms, 400ms+
Jitter
How much latency varies from one packet to the next. Voice and video need packets to arrive at a steady pace to reassemble smoothly — even a good average speed can’t fix uneven timing.
Too high: choppy or robotic-sounding audio, even when the connection “feels” fast.
0ms, 30ms, 50ms, 100ms+
Packet loss
The percentage of data that never arrives at all. Codecs can mask a small amount, but there’s a hard limit to how much they can cover for.
Too high: garbled words, frozen frames, and eventually dropped calls.
0%, 1%, 3%, 5%+
Minimum requirements for a good call
Per-call figures. An office running several calls at once needs these numbers multiplied by the number of simultaneous users, plus headroom for everything else on the network.
| Scenario | Download | Upload | Latency | Jitter | Packet loss |
|---|---|---|---|---|---|
| Single voice call | 100 Kbps | 100 Kbps | <150 ms | <30 ms | <1% |
| 1:1 HD video call | 1.5 Mbps | 1.5 Mbps | <150 ms | <30 ms | <1% |
| Group video conference (4–6 people) | 2.5–4 Mbps | 3 Mbps | <150 ms | <30 ms | <1% |
| Screen share added to a call | +1 Mbps | +1 Mbps | — | — | — |
| Office of 10, calls only | 1 Mbps | 1 Mbps | <150 ms | <30 ms | <1% |
These are minimums for calls to hold up — not a comfortable margin. We generally recommend planning for at least double the minimum on upload, since that’s the direction most connections run short.
DIA vs. business broadband
The two most common ways to get internet into an office, and why they behave differently under a video call.
DEDICATED
Direct Internet Access
A circuit reserved entirely for your business, with symmetrical speeds and a bandwidth guarantee backed by an SLA.
- + Guaranteed, symmetrical bandwidth — upload matches download
- + Not shared with other businesses or households
- + SLA with defined uptime and repair-time commitments
- + Static IPs included as standard
- – Higher monthly cost than broadband
- – Longer install lead times in some areas
SHARED
Business broadband
Cable or shared fiber service, sold to many businesses and homes over the same local infrastructure.
- + Lower monthly cost
- + Usually faster to install
- – Shared with neighbors — speed can dip at peak times
- – Upload is typically a fraction of download speed
- – Best-effort service, no SLA on uptime or speed
- – Static IPs often cost extra, if offered at all
Test your connection
Run the C9 Speedtest to see where your current connection actually lands against the numbers above. It opens in a new tab so you don’t lose your place on this page.
Send your results to Cleod9
Enter the numbers your test just showed you, and our team will follow up with what they mean for your setup — no obligation.
Get a quote on a better connection
Tell us what you’re working with and what you need, and we’ll put together options — DIA or broadband — sized to your call volume.
Common questions
What internet speed do I need for VoIP calls?
A single VoIP call needs about 100 Kbps of upload and download. A 1:1 HD video call needs roughly 1.5 Mbps in each direction, and a group video conference needs 2.5–4 Mbps download and at least 3 Mbps upload. Multiply by the number of simultaneous calls for an office estimate, and add headroom for everything else on the network.
What is good latency for VoIP?
One-way latency under 150 milliseconds is considered good, per ITU-T G.114 guidance. Between 150–250ms, callers start noticing delay and talking over each other. Above 250–300ms, conversation becomes difficult to hold naturally.
What is jitter and why does it affect call quality?
Jitter is the variation in latency from one packet to the next. Voice and video need a steady arrival pace to reassemble smoothly, so uneven timing can make audio sound choppy even when average speed looks fine. Under 30ms is generally unnoticeable.
How much packet loss is acceptable for VoIP?
Keep packet loss under 1% for reliably clear calls. Between 1–3%, expect occasional garbled words. Above 3%, calls get noticeably choppy, and above 5% they’re often unusable.
What’s the difference between DIA and business broadband?
DIA is a dedicated circuit reserved for your business, with symmetrical speeds and an SLA-backed guarantee. Broadband is shared with other subscribers, usually far slower on upload than download, and runs best-effort with no guarantee — so speed can dip at peak times.
Do I need a static IP for VoIP?
Not strictly, but it makes hosted PBX setup, firewall rules, and remote support far more predictable, and it’s often required for SIP trunking or a site-to-site VPN. Most DIA circuits include static IPs; broadband plans usually charge extra for them.