Your firewall should allow outgoing & incoming UDP to the public internet
We utilize Websocket connections so HTTPS / WebSocket / Secure RTP should be allowed
Local network conditions have the biggest impact on voice quality. Jitter, latency, and packet loss can be the biggest contributors to voice quality issues in any VoIP network.
Latency: High latency can substantially degrade a caller's experience. While there will always be some latency between the codec algorithm, the jitter buffer, and network traversal, the goal is to keep this to a minimum. Callers typically start to notice the effect of latency once it breaches 250ms, and find latency above ~600ms to be nearly unusable. Here are some strategies to minimize latency on your network:
- Some lower bandwidth fixed internet connections can often have higher latency. If possible, upgrade your internet connectivity.
- Stick to high-bandwidth connections. Mobile networks such as LTE (mobile 4G Data) can often have high latency.
Jitter: Packet loss, most frequently jitter-induced packet loss, can make a big impact on your VoIP call quality. Wi-Fi can be particularly bad for creating jitter. Here are some strategies to minimize jitter on your network:
- Reduce packet conflicts on Wi-Fi by reducing the number of devices operating on the same channel.
- Avoid large data file transfers over the same Wi-Fi environment concurrently with voice.
- Avoid buffer bloat, which can result in high latency, and bursts of jitter. We recommend ensuring your router is configured with the low buffer size, as high jitter cannot be masked by a buffer without introducing artificial delay, and often choppy audio.Note: Not all routers allow for configuring buffer sizes, but some routers ship with defaults which are not optimized for real-time VoIP networks. Open-source routers, enterprise-grade routers and gamer-oriented routers are good candidates for providing the right configuration options and defaults.
If you have addressed the above issues and continue to have jitter related impact on your voice quality, you may consider configuring your router with QoS rules to prioritize traffic on the above media UDP ports. Given the large range of UDP ports, you should only do this with prior consideration to what other traffic may be flowing in that port range.
By following this guide, you can significantly improve quality of service for the wireless voice applications and reduce or eliminate dropped calls, choppy speech, fuzzy speech, buzzing, echoing, long pauses, one-way audio, and issues while roaming between access points.
3 key metrics for voice quality:
- Network MOS - The Network Mean Opinion Score (MOS) is the network’s impact on the listening quality of the VoIP conversation. The score ranges from 1 to 5, with 1 being the poorest quality and 5 being the highest quality.
- Packet Loss Rate - The packet loss rate is the percent of packets that are lost during transmission.
- Interarrival Jitter - Interarrival jitter measures the variation in arrival times of packets being received in milliseconds (ms).
Below is a summary of the best practices to provide the best voice quality over wireless.
Perform a pre-install RF survey for overlapping 5 GHz voice-quality coverage with -67 dB signal strength in all areas. (Use Wifi Analyzer App)
If possible, create a new SSID dedicated to your voice over IP devices.
- Set Authentication type to 'Pre-shared key with WPA2'
- Set WPA encryption mode to 'WPA2 only'
- Enable '5 GHz band only'.
Enable 'Traffic shaping' on the SSID to prioritize all voice traffic
SIP 5060 UDP / TCP - RTP 10000-20000 UDP - internal Network / UDP 65550 if Vibe goes via Firewall
Set DSCP to '46 (EF - Expedited Forwarding, Voice)' for RTP