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Website Speed Optimisation: A Practical Guide
1 Sep, 2025
Free Tool
VoIP Network Readiness Checker
Assess whether your current network infrastructure can support a VoIP phone system, and get upgrade recommendations if needed.
Enter Your Network Details
Your broadband download speed in Megabits per second
Maximum simultaneous phone calls at any one time
VoIP Bandwidth Requirements by Codec & Concurrent Calls
| Codec | Per Call (Kbps) | 5 Calls | 10 Calls | 25 Calls | 50 Calls |
|---|---|---|---|---|---|
| G.711 (HD Voice) | 87 Kbps | 0.44 Mbps | 0.87 Mbps | 2.18 Mbps | 4.35 Mbps |
| G.729 (Compressed) | 32 Kbps | 0.16 Mbps | 0.32 Mbps | 0.80 Mbps | 1.60 Mbps |
| G.722 (Wideband) | 80 Kbps | 0.40 Mbps | 0.80 Mbps | 2.00 Mbps | 4.00 Mbps |
| Opus (Adaptive) | 40–80 Kbps | 0.20–0.40 | 0.40–0.80 | 1.00–2.00 | 2.00–4.00 |
Bandwidth figures include protocol overhead (IP/UDP/RTP headers). Actual usage varies by codec settings, silence suppression, and network conditions. We recommend reserving 30% additional headroom for data traffic. Talk to our VoIP team
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