Troubleshooting VoIP Phone Problems

Caller: Hello, can you hear me? ​

Operator: I am sorry. Hello, can you speak up? I can’t hear you.  ​

​Caller: There is something wrong with my phone or something, can you help me? ​

​Operator: You got to hang up and call back again. I am so so sorry.  ​

​Frustrating, isn’t? ​Does this ever happen to you?  ​At this age, we hope this will be just a thing of the past. After all, technology has grown by leaps and bounce, and this should not have happened.  ​

Sad to say, this can happen from time to time. Nothing is foolproof, after all. Something might go astray. But some technologies only require some tweaking from time to time in order to function well.  ​

​Such is the case of VoIP is a phone service that has problems that can be quickly resolved. That is as long as you can identify what kind of problem you are facing. Then getting the know-how of what method can fix it is the next logical step.  ​

​Common VoIP phone problems

First, we need to discuss the VoIP phone problems that are common. Then we will move on to how to fix these setbacks.  ​

• Ineffective Calls  ​

If you have unable to make outbound calls, you may have two routers dropping certain critical packets of data. That is not a router configuration problem, but it has to do with the network layout. ​

There will be numerous problems with VoIP applications. It is mainly only if specific protocols are processed by the Application Layer Gateway (ALG) and then rewritten for better flow through a firewall or NAT (Network Address Translation).  ​

• Calls that has no sound  ​

That may happen because a firewall is blocking the Real-time Transport Protocol (RTP) packets from flowing. There is some adjustment in the router when dealing with the SIP protocol to rewrite packets using RTP. ​

• Audio is choppy  ​

This common VoIP problem is often attributed to bandwidth capacity. When you are hearing someone else cut in and out, that is a download bandwidth problem. And when others hear you cut in and out, it’s upload bandwidth that is problematic. ​

That also often affects high-bandwidth services like audio and video. ​

• Hearing echoes during calls  ​

When this happens, there are three potential culprits: the headset lag, device, or network latency. ​

• Calls ends abruptly   ​

That usually occurred after 11 minutes into the call. This problem happens more often with outbound calls on high-volume networks. ​

There are three guilty parties here: not having the most up-to-date firmware on your device; it might be the UDP Timeout, or the UDP network traffic is too fast.  ​

Troubleshooting procedures

Now that you can identify the VoIP problems, it is time to move on to fix them on your own. Here are some troubleshooting procedures:  ​

1. Ineffective Calls (Unable to Make Calls)  ​

When this happens, disabling the SIP ALG might be a good idea. Also, check if there are a double NAT or two routers. That is what is inhibiting your flow of packets. It also helps if the VoIP phones are on a Virtual LAN (VLAN).  ​

2. Calls that have no sound (Call Connection with no sound)  ​

​To resolve this issue check the firewalls. You may resort to opening the ports. Chances are, it might not be allowing any flowing traffic to pass. 

3. Audio is choppy (Choppy audio) ​

Here there is a need to verify your network stability. Have at least three VoIP speed testers. Afterwards, take the average speed of all three.  ​

If the bandwidth is lower than expected and not consistent, talk to your Internet Service Provider (ISP). ​

4. Hearing echoes during calls (Echoes during calls)  ​

​Check all possible cause of echoes during calls. A Bluetooth headset is advisable, but it far from perfect. Try swapping a different headset in its place to see or hear if there is still an echo.  ​

As mentioned earlier, this has three culprits or maybe a combination of the two or all. It will either be one of the three or a combination of headset lag, device, or network latency. ​

Unplugging and plugging in all devices is also a good measure. Have a test call while you are at it.  ​

When the problem persists, this can be a problem related to network stability. The network needs some improvement.   ​

5. Calls ends abruptly (Dropped Calls)  ​

​There is two way to fix this common issue. First, the router settings need some adjusting to allow for longer UDP timeouts. Second, there is a need to switch devices to use TCP. ​ The default UDP connection timeout is 30 seconds. Try to increase it to 60 seconds—some tinkering in the firewall access rules is in order.  ​Another way to solve this is to use TCP instead.  ​

Other issues

In addition, apart from the five common VOIP phone problems mentioned above, there are other issues too. These issues are also inherited with the phone system. Because it may rear its ugly head one way or the other. These are: delayed in inter-office calls; calls go straight to voicemail; one phone works while the other doesn’t; and low-quality audio. 


Admittedly, this is too technical and is better resolve by experts. But a few reading and tweaking here and there can help you resolve some issues with your VoIP system. It is all a matter of being familiar with your VoIP systems like the Application Layer Gateway (ALG) and your firewall or NAT (Network Address Translation), then identifying which port to plug what wire. Again, there is no stopping you from going above and beyond. Moreover, learning the intricacy of what makes your business roll is a noble thing to do. ​Moreover, as an English writer, artist and well-known critic, John Ruskin, said: “When love and skill work together, expect a masterpiece.” ​

If a critic like Ruskin put it that way, who are we to argue? Any business, in practice, is a businessman’s masterpiece. It is better to know the ins and outs of one’s business, even if it gets too technical.  ​However, if you are not too certain about what you are about to do, it would not be a bad thing to calling for help. It would rather be a wiser thing to do. But if you consider yourself as being adventurous enough and got the courage to go through trial and error, by all means, carry on.

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