Network requirements for voice

500 kbps per agent, a firewall that lets the media through, and a browser that supports WebRTC. The figures your network administrator needs.

500 kbps per agent, a firewall that lets the media through, and a browser that supports WebRTC. These are the figures to hand your network administrator, because a connection that feels fast for browsing can be poor for voice: browsing tolerates latency, jitter and packet loss, and calls do not.

Bandwidth

500 kbps per agent providing voice support. Fifty agents therefore need a line of at least 25 Mbps, and that is on top of everything else the office does.

What the firewall has to allow

Ports alone are not enough for the third row. The fallback runs from regional edge locations with their own IP ranges, so a firewall that opens the ports without allowing the ranges for your region still blocks it. Dublin and Frankfurt are the ones that matter from here.

That fallback is not optional, whatever the name suggests: it is what keeps audio flowing when the direct media path is blocked, and an account without it works until the day it does not.

Signalling cannot be allowed by IP range at all; it has to be done by domain, and that is a fixed list rather than something derived from your account. The pubsub addresses for your pod are the part that does depend on you. Ask pluscloud for the current list rather than guessing at a wildcard.

The browser

Calls run in the browser over WebRTC, so it has to be a browser that supports it: Chrome or Firefox. If you want DSCP tagging so your network can prioritise the call traffic, that is the latest non-beta Chrome only.

Wired, at both ends of the sentence

Zendesk's recommendation is blunt: a wired network with Wi-Fi turned off gives better results, with wired 3.5 mm jack headsets for agents and a wired internet connection.

This is the single change that fixes the most call quality complaints. An agent two rooms from the access point has packet loss that never shows up in a speed test and is clearly audible on a call.

What to check before you start

• The firewall allows the ranges and ports above.
• Agents are wired, or at least close to a good access point.
• Nothing saturates the network at predictable times, such as backups.
• Home workers have a connection that holds up, and a headset.

Quality of service, where you can

On a managed network, prioritising voice traffic protects calls when the network is busy. That is work for whoever runs your network, and it is what stops a large download degrading every call.

See also

• Call quality is poor: what to check
• Testing your voice setup
• System requirements and supported browsers