Here's an industry secret: when cloud phone calls sound bad, the phone provider is rarely the culprit. HD voice codecs are excellent and carrier networks are solid. The problem lives in the last hundred feet — your internet connection, your router, your Wi-Fi. The good news: that means you can fix it.
The three numbers that decide call quality
- ▸ Bandwidth: each HD call needs only ~100 Kbps each way. Twenty simultaneous calls fit in 2 Mbps — bandwidth is almost never the real issue on business internet.
- ▸ Latency: the round-trip delay. Under 150ms one-way is fine; past 300ms conversations start talking over each other.
- ▸ Jitter: variation in packet arrival timing — the real villain. Jitter above ~30ms causes the choppy, underwater, robot-voice artifacts people blame on 'bad VoIP.'
Symptom → cause, quickly
- ▸ Choppy/robotic audio: jitter or packet loss — usually Wi-Fi interference or a saturated upload link
- ▸ One-way audio: firewall/NAT issue — SIP ALG is the usual suspect (see below)
- ▸ Echo: usually a headset/speakerphone acoustics problem, not the network
- ▸ Calls dropping at exactly N minutes: router session timeout settings
- ▸ Bad quality every day at the same time: something on your network (backups, cloud sync, the lunch-hour streamers) is flooding the upload
The five fixes that solve 90% of problems
- ▸ 1. Disable SIP ALG on your router. It's enabled by default on many routers and mangles VoIP traffic. This single setting causes more one-way-audio tickets than everything else combined.
- ▸ 2. Turn on QoS and prioritize voice traffic so a big file upload can't starve your calls
- ▸ 3. Wire the desk phones. Ethernet doesn't have interference; Wi-Fi does. Save wireless for the mobile apps.
- ▸ 4. Check your upload, not your download. Business cable plans with 300 down / 10 up fail on the 10.
- ▸ 5. Replace the ISP's combo modem/router if it's more than a few years old — aging consumer gear is a jitter factory.
What your provider owes you
A serious platform monitors call quality metrics (MOS scores, jitter, packet loss) per call and will show you the data instead of guessing. Talk Is Cheap support reads those graphs with you, ships pre-provisioned phones with sane QoS defaults, and fails calls over to mobile apps automatically when your office internet has a bad day — because 'sounds great' is the whole product.