Echo, delay and dropped calls: how to find and fix audio problems on IP telephony
Sado AI team · · 4 min read
In short
Most audio problems on IP telephony come from four places: Wi-Fi or a busy internet line (choppy, delayed audio), NAT and SIP ALG settings on the router (one-way audio, calls dropping at 30 seconds), a loud speakerphone or cheap headset on the other end (echo) and old analogue equipment (noise). First find out whether it affects all calls or one phone, and on which side it’s heard. Plug the phone into a cable, give voice priority, and send your provider exact examples: time, number, what was heard.
Cause and fix by symptom
| What you hear | Usual cause | What to do |
|---|---|---|
| Your own voice coming back (echo) | Speakerphone or cheap headset on the other end; an analogue gateway | Use a headset, turn the speaker down, enable echo cancellation in the gateway or PBX |
| You talk over each other, replies lag | Delay: Wi-Fi, VPN, busy internet, a distant server | Plug the phone into a cable, test without VPN, ask the provider for a closer server |
| Choppy or robotic audio, missing words | Lost packets: Wi-Fi, a busy line, weak mobile signal | Give voice priority (QoS), move big uploads to another time |
| You hear them, they can’t hear you | NAT, SIP ALG or closed ports on the router | Turn off SIP ALG on the router, open the ports your provider names |
| The call drops at about 30 seconds | The router loses a SIP message (NAT, SIP ALG) | Turn off SIP ALG and check with the provider |
| Hiss or crackle | Old cable, an analogue line, a faulty headset | Try another cable and another headset |
How to find the cause: in this order
- All calls or one phone? If it’s one place, the cause is that phone, headset or Wi-Fi.
- Which side: do you hear badly, or does the customer? Ask both.
- When: all day or at certain hours? If it gets worse in the afternoon, the line may be busy then.
- Move the phone from Wi-Fi to a cable and repeat the same call.
- Test over another connection, such as mobile internet. If the problem stays, the cause may be on the provider’s side.
- Send the provider exact examples (list below).
What to tell your provider
- The date and exact time of the call, to the minute.
- From which number to which, incoming or outgoing.
- What was heard: echo, breaks, one-way audio or a drop, and at which second.
- How often: every call, or once or twice a day.
- The call recording, if you have one.
A vague “the sound is bad” gets a vague answer. With three exact examples the provider finds the cause faster.
Example: a training centre
At the Ilm Nuri training centre, receptionists talk through a phone app over Wi-Fi. For example, every day after 3 p.m. parents say “you keep cutting out”. A check shows that teachers upload lesson videos at exactly that time. The receptionists’ phones were moved to a cable and the router gave voice priority, and the problem went away. This is only an example; your cause may differ, but the order of checks is the same.
On AI operator calls
If Sado’s AI operator is connected to your number directly through the provider, the call doesn’t pass through your office internet or router: it goes from the provider straight to Sado. So office Wi-Fi problems don’t touch these conversations. When the operator transfers a call to a staff member, the sound depends on that person’s phone and connection.
Each call’s recording and transcript are kept in the portal: if a customer says “it was hard to hear”, you listen to the recording and quickly see which side the problem was on. More: AI operator for incoming calls, connecting your own number and questions about Sado. Try it live or call 78 778 01 23.
Questions
What is SIP ALG and why turn it off?
It’s a feature switched on in many routers that tries to “fix” SIP messages but often breaks them. One-way audio and drops at 30 seconds often come from it. Check with your provider before turning it off.
Can an IP phone work over Wi-Fi?
Yes, but a wired connection is steadier. On Wi-Fi, give voice priority and don’t talk far from the router or behind walls.
How do I tell if the problem is ours or the provider’s?
Make the same call over another connection, such as mobile internet. If the problem disappears, it’s in the office network; if it stays, write to the provider with examples.