Direct answer
Every claim is sourced below
Plan for 100 Kbps per concurrent voice call standard or 150 Kbps for HD voice, and 2-3 Mbps per HD video participant, all sustained on the upload side [1][2][3]. Keep latency under 150 ms, jitter under 30 ms, and packet loss under 0.5%, then add roughly 20% headroom for peak hours and background cloud traffic [1][3].
Segment fit matrix
| Feature | 10 seats | 50 seats | 250 seats |
|---|---|---|---|
| Voice upload bandwidth (HD) | ✅ Required | ✅ Required | ✅ Required |
| Video conferencing headroom (2-3 Mbps per stream) | ✅ Required | ✅ Required | ✅ Required |
| QoS on router and switch | 🟡 Recommended | ✅ Required | ✅ Required |
| SD-WAN with voice priority queue | — Skip | 🟡 Recommended | ✅ Required |
| Backup internet circuit for failover | 🟡 Recommended | ✅ Required | ✅ Required |
| Latency budget under 150 ms one-way | ✅ Required | ✅ Required | ✅ Required |
| Pre-deployment network assessment | 🟡 Recommended | ✅ Required | ✅ Required |
Key terms
Outcome metric
Number of simultaneous voice sessions active during peak business hours.
Technical dependency
Uncompressed voice codec using 64-87 Kbps per call for high audio quality.
Technical dependency
Compressed voice codec using 24-32 Kbps per call where bandwidth is tight.
Outcome metric
Variance in packet arrival timing, should stay under 30 ms for clean voice.
Technical dependency
Router and switch policy that prioritizes voice packets over file transfers and backups.
Providers to consider
Market-leading cloud communications platform combining voice, video, messaging, and contact center. Named a Leader in the Gartner Magic Quadrant for UCaaS for 10 consecutive years as of 2024. Best for mid-market and enterprise businesses seeking an all-in-one ucaas platform with global pstn coverage.
Video-first UCaaS platform with cloud PBX and team messaging built on its enterprise video footprint. Zoom Phone surpassed 5 million paid seats as of 2023, making it one of the fastest-growing cloud PBX deployments. Best for organizations already on zoom video seeking to consolidate voice and meetings on one platform.
UCaaS voice add-on tightly integrated with the Microsoft 365 ecosystem. Microsoft Teams has over 320 million monthly active users as of 2024, providing a massive installed base for Teams Phone upsell. Best for enterprises standardized on microsoft 365 that want to eliminate a standalone pbx.
Integrated UCaaS and CCaaS platform on a single cloud architecture. 8x8 XCaaS (Experience Communications as a Service) unifies UCaaS and CCaaS on one platform, a differentiator recognized by Gartner in 2024. Best for mid-market companies that need both unified communications and contact center on a single contract and platform.