Troubleshooting poor Voice Quality in VoIP

How to Troubleshoot Broken Voice with a VoIP service.

Businessman working at his desk and on a cell phone making test calls..Even with larger more robust Internet pipes there might be occasions when your business VoIP experiences poor quality or broken voice. Broken voice can best be described as bits of voice missing from the conversation and can occur on the inbound voice, the outbound voice or both. This condition, also referred to as choppy voice, occurs when jitter on the network causes packet delay longer than what can be reassembled into a proper voice sequence with existing hardware. The latent packets are then discarded leaving bits of voice missing.

Look for the Cause; Here's Where to Start:

The following steps should be taken if your VoIP service has been performing well, but for some reason is now experiencing periods of degraded (poor quality) voice, best described as broken voice. If you're VoIP service has just been installed then you should start by looking at the LAN and how it is designed to make sure that best practices have been followed, such as making sure enough bandwidth is present, configuring QoS on the router for Voice prioritizing, and creating separate VLANs for Voice and data.

  • Make test calls to an outside line and determine where the broken voice is being heard. For example, the party on the other end (outside your network) hears your voice broken, or you hear the caller breaking up.
  • Make extension to extension calls to see if calls are experiencing issues inside the LAN. If you have an in-house Asterisk or IP phone system then this will tell you is the issues are related to inside the network or outside with the carrier.

Broken voice occurring with an On-Premise VoIP system

Calls inside extension to extension are ok, not outside calls.

If you have an in-house Asterisk phone system and you are getting broken voice on outside calls, but not extension to extension calls, you can then use a tool, like Ping-Plotter that can show exactly where the bottleneck resides. The results can then be used to open up a ticket with your carrier, if it's on one of their routers.

Calls extension to extension are experiencing broken voice.

Calls breaking up extension to extension with an in-house phone system points to a network bottleneck. This could be anything from network saturation to mismatches of duplex settings.

Broken voice with business hosted VoIP

Using extension to extension calls to isolate if the issue is occurring only on the WAN cannot be used for hosted VoIP, because even extension calls are traveling outside the LAN and back again. Broken voice (choppy voice) suddenly occurring with a hosted VoIP service usually points towards the WAN, but before making that assumption, check if any other issues are occurring on the LAN, such as slow Internet browsing speeds. Perhaps someone is using an app grabbing too much bandwidth. (QoS should be set to prioritize voice to prevent these occurrences). If everything looks good, then try some ping tests to see if any packet loss is occurring or other network bottlenecks.

A note about the occasional broken voice with a hosted VoIP service.

Internet traffic travels over multiple networks before getting to its destination. In most cases everything works very well, however there will be times when delays will cause problems. If these delays are above a certain level (over 150ms), then a degradation in voice quality will be experienced. As the delay increases, so will the problems. These delays are immediately noticeable in conversations, but are usually short lived and become corrected by the networks where the problem exists. Cell phones experience issues all the time, but users have grown accustomed to them. VoIP is great technology, it lowers costs and increases productivity, but does come with some downsides; the occasional period of broken voice may be one of them.