If you run a call center, you know how fast a choppy call or weird echo can turn a routine day into a mess. This guide is for IT admins, help desk folks, and anyone who’s the “phone person” at work—especially if your team uses Five9. Let’s get real about call quality: what goes wrong, what you can actually fix, and what’s usually a waste of time.
1. Get Specific: Identify the Actual Call Quality Issue
First things first: “bad call quality” means different things. You need details before chasing ghosts.
Common complaints: - Choppy audio or voice dropouts - Echo or feedback - Delay (lag) between speaking and hearing - Robotic or distorted voices - Calls dropping or failing to connect
Pro tip: Always ask for call examples—date, time, who was on the call, and what exactly happened. Vague reports (“calls sound bad”) aren’t helpful.
What to skip: Don’t jump straight to blaming Five9 or your ISP. Most problems start closer to home: user devices, local network, or even the headset.
2. Start Local: Check the Agent’s Setup
Most call quality issues start at the user’s end. Before you dive into deep technical weeds, check the basics.
Headsets and audio devices: - Is the agent using a wired, USB headset? Bluetooth headsets are notorious for glitches. - Cheap or worn-out headsets distort sound. Try swapping in a known-good headset.
Computer performance: - Is the agent’s computer maxed out? Video calls, a dozen Chrome tabs, or background downloads can kill call quality. - Restart the computer. Simple, but it really solves a surprising number of issues.
Network connection: - Is the agent on Wi-Fi? If yes, try plugging in with an Ethernet cable. Wi-Fi is flaky, especially in crowded offices or old buildings. - Are there other heavy users on the network? Streaming video or big file downloads can eat up bandwidth.
Quick checklist: - Wired headset (not Bluetooth) - Wired network (not Wi-Fi) - Computer not overloaded
What to ignore: Don’t waste hours fiddling with obscure VoIP settings until you’ve checked these basics.
3. Rule Out Home/Office Network Problems
If the agent’s setup checks out, the next likely suspect is the network between them and Five9.
Run a Speed Test
- Use speedtest.net or fast.com from the agent’s computer.
- Five9 recommends at least 100 kbps up and down per call, but realistically you want more buffer.
- Look for high latency (ping over 100ms) or jitter (variation in latency).
Test for Packet Loss
- Open a Command Prompt or Terminal.
- Ping Five9’s server or a stable public address (like 8.8.8.8).
- If you see packet loss (>0%), that’s a red flag.
Check for Network Congestion
- Heavy network use—large backups, streaming, or other VoIP apps—can cause choppy calls or lag.
- Try a call early in the morning or late at night. If quality improves, your network’s probably overloaded.
What matters: Consistent, low-latency, low-jitter, and no packet loss.
What doesn’t: Super high download/upload speeds aren’t useful if your connection is unstable or congested.
4. Inspect Firewalls and Security Settings
Five9 calls travel over the internet, and overly aggressive firewalls or security appliances can mangle VoIP traffic.
What to check:
- Are the required Five9 ports open? Five9’s documentation lists the ports; double-check your firewall rules.
- Is your firewall doing “deep packet inspection” or other fancy filtering? That can break voice packets.
- Are you using a VPN? Some VPNs route traffic in weird ways or block UDP (used by most VoIP). Try without the VPN.
Pro tip: Temporarily bypassing the firewall (for testing) can help isolate if it’s the culprit. Just don’t forget to turn it back on.
What to skip: Don’t just “allow all” to the internet in a panic. That’s a security nightmare. Stick to Five9’s published network requirements.
5. Dig into Five9 Settings and Dashboards
If you’ve ruled out device and network issues, it’s time to look inside Five9.
Agent Console/Softphone Settings
- Are agents using the latest version of the Five9 softphone? Outdated versions can cause all kinds of weirdness.
- Is the correct microphone and speaker selected in the app?
- Are agents switching between devices mid-call? That can confuse the software.
Five9 Dashboards
- Five9’s admin dashboard shows real-time call stats. Look for:
- Call latency (should be under 150ms for a good experience)
- Jitter (ideally under 30ms)
- Packet loss (should be 0% for stable calls)
- Check for patterns: Is it all calls, or just certain agents/times?
Call Recordings and Logs
- Use call recordings to confirm if issues are one-sided or both ways. If only the agent sounds bad, it’s likely their end.
- Five9’s logs can show error messages or call drops that aren’t obvious to users.
What to ignore: Don’t trust gut feelings (“It feels like Five9 is slow today”). Use the data—Five9 dashboards and your network tools—to confirm.
6. Test with a Clean Setup
Still stuck? Time for a controlled test. Set up a “golden” environment: - Known-good computer (no other apps running) - Wired headset - Wired network - No VPN or firewall interference
Have an agent log into Five9 from this setup and make a test call. If it works fine, you know the problem is with the original agent’s setup, not Five9 or your network as a whole.
If it’s still bad, it’s either a Five9 service issue or something weird with your ISP or internet routing.
Pro tip: Sometimes, routing issues with ISPs can cause problems even if your local network is fine. Try switching to a different internet connection (like a mobile hotspot) to test.
7. When to Call Five9 Support
If you’ve ruled out everything on your side and the problems are affecting multiple agents or locations, it’s time to escalate.
What you’ll need: - Specific call examples (dates, times, agent IDs, call types) - Results of your speed/jitter/packet loss tests - Five9 error logs, if available - Description of what you’ve already tried
Being able to say, “We’ve tested multiple devices, networks, and headsets, and the issue persists,” gets you past the script faster.
What to skip: Don’t just say, “Calls are bad.” Vague tickets take longer to resolve.
8. Ignore the Myths
There’s a lot of noise around VoIP troubleshooting. Here’s what not to stress about: - Bandwidth upgrades: Unless you’re running out of bandwidth, increasing your internet speed won’t fix packet loss or jitter. - Exotic codecs: Five9 uses standard codecs that work fine out of the box. Tinkering rarely helps. - Random Windows tweaks: Registry hacks and “performance boosters” are mostly snake oil.
Instead, put your energy into getting the basics right: good hardware, clean network, and solid configuration.
Keep it simple: Most call quality issues boil down to a handful of causes—bad headsets, flaky Wi-Fi, or a clogged-up network. Fix those first before hunting for obscure bugs. Keep notes on what works for your team, and don’t be afraid to redo the basics whenever problems pop up. The less you overthink it, the faster your agents (and you) can get back to work.