My SoftPhone is Dropping Calls! What do I do?

How to troubleshoot dropped voip calls

Voice over Internet Protocol (VoIP) services like SoftPhone continue to revolutionize the business world. Companies of all sizes can reap its rewards, including saving up to 30% on phone bills and increasing productivity rates by 20%.

While this technology can be beneficial, issues like dropped calls threaten to halt your productivity. 

Why is my Softphone dropping calls? Read on to learn about what causes VoIP calls to drop and get some tips for troubleshooting SoftPhone. 

Failed Connection Acknowledgment Signal

Session Initiation Protocol (SIP) is the signaling protocol that’s responsible for establishing your VoIP call. When you make a call, the device on your recipient’s end sends a message to yours verifying the connection. Once that happens, you’ll generate an acknowledgment called a SIP ACK and can continue with the call.

Occasionally, SIP ACKS take too long to generate. This will cause the call to end prematurely. If you notice calls failing within 30 seconds of making them, a late connection acknowledgment signal is the likely culprit.

The Solution

A bug in the SIP server causes this issue. You’ll likely need to enlist the help of an IT professional to reconfigure the NAT transversal logic in your on-reply routes.

SIP Timer Issues

Your SIP timer attempts to detect failed calls by sending Invite or Update requests. These usually occur at regular intervals, with around 15 to 30 minutes being the most common.

When the system is working as intended, the line is kept open and the call is allowed to continue. However, these requests are sometimes late. If your device doesn’t receive the request when it expects to, it ends the call.

This is perhaps the easiest VoIP call-dropping issue to diagnose. If you notice your calls failing at 15-minute intervals, you can be reasonably sure that the SIP timer is to blame.

The Solution

SIP timer problems are relatively easy to solve. To do so, you’ll need to view your system’s min-se settings. Min-se refers to the minimum value of the session interval. It’s always expressed in seconds.

Try raising the value, so your device has more time to receive requests before shutting down the call.


Talk-off refers to the phenomenon of your phone service misidentifying your voice as a dial tone multiple frequency (DTMF) signal. You’re likely already familiar with this. It’s the beeping tone you hear over the line when you dial a phone number.

In some instances, your phone service can inaccurately identify a voice as a DTMF signal. This can cause the call the drop or initiate a hold.

There are a few signs that talk-off could be the cause of call-dropping problems. The most obvious one is if you or the other party hear the DTMF tones while on the call. Calls dropping while someone is talking could be another indication.

The Solution

Talk-off is another relatively easy issue to troubleshoot. The first step is to try adjusting the gain on your microphone. Lowering it usually solves the problem.

You need to lower your system’s DTMF sensitivity if that doesn’t solve the issue.

RTP Inactivity

VoIP systems use a protocol called Real-time Transport Protocol (RTP) to transmit your voice. This protocol expects to relay audio, so it actively monitors the line for audible activity. 

This is usually a good thing. When no audio is detected, it shuts down the call to save bandwidth.

However, silence can disrupt the flow of RTP packets. If you notice calls dropping when someone stops talking or uses the mute function on their microphone, the system can incorrectly assume there is no activity on the line and end the call.

The Solution

Changing your device’s silence suppression system can alleviate this issue. You can adjust it easily through the device’s menu.

Network Issues

Sometimes, the cause of your dropped calls has nothing to do with your VoIP setup. Everything could be working as it should, but an issue with your network can cause you to lose connection.

Many hybrid landline/VoIP systems experience this problem. Older analog phone systems can take over a line and cause a call to drop. 

Too many routers on the same network can also spell trouble for VoIP systems. They may introduce unfriendly NAT transversal or serial peripheral interface (SPI) that can prevent voice packets from making it to your headset.

Your network problems could also be something simple. You could have a loose cable, a damaged port, or a malfunctioning router.

The Solution

There isn’t a one-size-fits-all solution if network problems are to blame for your dropped calls. The best course of action is to upgrade any old equipment and make sure that everything is properly plugged in and is free of damage.

You should also ensure that your routers are properly configured and have the necessary bandwidth.

Time Limit Exceeded

Some calls are automatically dropped by the service provider once you exceed the time limit. It’s usually around 2 hours.

This can be a beneficial service because it helps prevent you from accidentally staying on a call and accruing a large bill.

If your calls are dropping at a specific point, you’ve likely reached your service provider’s time limit for a call.

The Solution

Stay mindful of the time limit while you’re on a call. If you notice it approaching but need to continue the conversation, hanging up and calling back resets the limit.

SoftPhone: The Next Generation of VoIP

If your SoftPhone is dropping calls, you could miss out on important business dealings. Several issues can cause dropped calls, so you need to get to the bottom of it quickly.

The good news is that SoftPhone troubleshooting is fairly simple. Many issues have relatively simple solutions.

DLS’s SoftPhone is the future of VoIP for businesses. With it, you can make VoIP calls on your smart device. You’ll have access to all the perks of a traditional VoIP in the palm of your hand.

Learn all about this incredible service and pick up more SoftPhone tips on our website.