Dropped calls caused by your network or device

Even when call quality is generally acceptable for long periods, unexpected call disconnections may still occur on some networks and for many different reasons. In some cases, calls may be dropped because of accumulated factors that cause network congestion, an unreliable internet connection, or an unexpected interference in the call stream that the application cannot recover from.

This article explains some of the most common causes of dropped calls when using Aircall.

Upload and download restrictions

Aircall calls work similarly to any streamed content, but with a key difference in how data is sent.

When you watch a movie on Netflix or listen to music on Spotify, most of the data is sent to your device from a remote location, and very little data is sent in the opposite direction. Aircall calls are bi-directional, which means your device sends data and that it receives data in roughly equal amounts.

This bi-directional format can cause issues with typical home-based internet connections. Unlike many corporate internet tariffs, it is common for home internet connections to have much lower upload throughput compared to download throughput.

As a result:

• Upload congestion may occur even when the internet is only being used minimally on the network.
• If this congestion accumulates, it can lead to eventual call disconnections.

Software interruptions

Some call drops may occur due to software running on the same device.

This can happen, for example, during conflicts with resource acquisition, when two different software applications each attempt to forcibly acquire physical peripherals and device resources at the same time.

Experimenting with closing commonly open applications on the device may help improve call connection stability.

NAT and firewall settings

Routers and firewalls often come preconfigured in ways that disrupt VoIP-related traffic, which can lead to poor call quality and dropped calls.

If your calls connect briefly and then disconnect shortly after, particularly around 20 seconds in, this is a classic sign that your firewall or router is passing initial call setup (signaling) but blocking the actual voice stream (media) once the call is established. Work through the following checks:

Steps

1. Disable SIP ALG on your router. SIP ALG (Application Layer Gateway) is a feature found on many routers intended to help VoIP calls, but it almost always causes problems with modern VoIP services like Aircall. Log into your router's admin panel and disable it entirely.
2. Disable port forwarding. If port forwarding rules are active on your router, try disabling them and test again.
3. Whitelist Aircall's required IPs and ports. See Firewalls, anti virus, and content blockers for the full list.
4. Confirm UDP traffic isn't being throttled or blocked. Aircall uses UDP for voice because it's faster than TCP. If your network forces TCP or restricts UDP, calls will disconnect after a short time. Confirm with your IT team that UDP is fully permitted.
5. Run a Network Diagnostics test. Open Aircall Workspace > Settings > Network Diagnostics and check your results. Please Network Diagnostics Panel for how to interpret them. A result of 0 or N/A means the diagnostic itself couldn't connect, which points directly to a firewall or network block.

Separately, an additional issue with NATs relates to the peer-to-peer (P2P) nature of VoIP calls. Due to historically abused P2P technologies, such as torrent-based file sharing, some networks may be configured to hinder this kind of network throughput, which can affect VoIP call connections. If your calls disconnect after a seemingly fixed duration, this may be related to how P2P traffic is treated on your network.

UDP and IP allowlisting

If your firewall is passing initial call setup (signaling) but blocking the actual voice stream (media), calls will often connect briefly and then drop shortly after. Confirm with your IT team that UDP traffic isn't being throttled or blocked, Aircall uses UDP for voice because it's faster than TCP, and if your network forces TCP or restricts UDP, calls can disconnect after a short time. Make sure all required Aircall IP ranges and ports are allowlisted; see Firewalls, anti virus, and content blockers for the full list.

Drop source

The source of a call drop is not always your own device or network. The other party on the call may also have their own connection difficulties that lead to disconnection.

If your calls are connecting and lasting a while before dropping unexpectedly, with no consistent pattern, this is typically a network stability issue, not Aircall dropping the call. Try the following before contacting Support:

Steps:

1. Switch to a wired Ethernet connection. Wi-Fi is the most common cause of intermittent call drops. If you're on Wi-Fi, try Ethernet and monitor whether drops stop.
2. Close background applications. Video calls, large file uploads or downloads, streaming, and browser-heavy workloads all compete for bandwidth and can interrupt the real-time voice stream.
3. Test from a different device, such as your mobile app or a second computer. If drops stop, the issue is tied to your original device or its network path, not Aircall. If drops continue on every device, the issue is your network.
4. Test from a different network, such as a mobile hotspot. If calls work perfectly there but drop on your usual network, your primary network's configuration is the cause.
5. Collect the Call IDs (UUIDs) of the affected calls for investigation. Please Collecting Call Examples (UUID/ID) for how to find these, then provide them to Aircall Support so engineers can trace the disconnect point.

At Aircall, it may be possible to detect whether the cause of the dropped call originated from your device or from the call recipient. If our team investigates and finds a BYE signal (the hang-up command) coming from the caller's side rather than from Aircall's servers, the disconnection originated outside of Aircall's control.

If call disconnections occur frequently and you would like help investigating, please contact Aircall Support so the issue can be reviewed.