Bandwidth Requirements and Network Best Practices

Bandwidth per call

Plan for about 100 Kbps per concurrent call using the G.711 codec. So a 10-line business making 10 simultaneous calls needs about 1 Mbps of headroom dedicated to voice. Most modern business internet connections have plenty.

QoS — prioritizing voice

Voice is more sensitive to latency and packet loss than to bandwidth. If your network is congested by file uploads, video calls, or backups, voice quality suffers first. Two ways to fix that:

• QoS / DSCP marking — configure your router or switch to prioritize voice packets (we use standard DSCP/ToS tagging and VLAN 802.1Q)
• Voice VLAN — isolate phones on their own VLAN with dedicated bandwidth

Common problems to watch for

• Consumer-grade Wi-Fi for desk phones — wire them instead, or use a managed AP
• Old SOHO routers that don't handle SIP cleanly — replace with a business-class router
• Double-NAT (cable modem + router both doing NAT) — bridge the modem

If you're seeing call quality issues, contact [email protected] — we can run diagnostics from our side to pinpoint where the problem is.