Published : March 25, 2021VoIP (Voice over Internet Protocol) allows you to make and receive calls over the internet. This means that the quality of your calls depends on how good your internet connection is.
If you have slow internet, you will likely experience high network jitter. For those unaware, jitter refers to the delay in sending data packets over your network connection. And the higher the jitter, the more interruptions you will experience in your VoIP calls.
In this article, we will discuss:
- What is network jitter?
- What causes jitter?
- How to measure jitter?
- How jitter affects VoIP call quality?
- Acceptable Jitter for VoIP
- How to fix jitter issues?
Let’s dig right in!
What Is Network Jitter?
Network jitter in VoIP refers to the situation where your internet connection sends voice packets inconsistently. In simple words, the information is not sent in the same order it is spoken. It is also possible that certain packets reach the customer quicker than other packets due to network congestion, leading to a jumbled conversation.
Network jitter is usually measured in milliseconds (ms) of delay. If the jitter is delayed by 40 or 50ms, your call quality will degrade massively.
What Causes NetworkJitter?
Since VoIP uses your internet connection to make phone calls, anything that affects your internet connection will also affect your call quality. And while the exact reason for network jitter is difficult to determine, here are some possible reasons:
- Overcrowded Network: Network congestion is one of the most common reasons for jitter. If you have too many devices connected to the same network, you will quickly run out of bandwidth, leading to data packets being dropped or delayed.
- Wireless Networks or Wi-Fi: Though Wi-Fi offers more mobility and flexibility to not stick to a desk, it is weaker than wired connections. And if you connect lots of devices (10+) to a single Wi-Fi, you will likely experience high jitter.
- Outdated Hardware: Our internet connections comprise a few pieces of hardware (cables, a modem, a router, and switches). An outdated modem or low-quality ethernet cable can negatively affect your VoIP call quality.
It is worth mentioning that sometimes high jitter might occur in a carrier network (i.e., on your internet provider’s side). Since, in this case, we cannot do anything, we will focus on the causes mentioned above.
How To Measure Network Jitter?
Measuring jitter is easy and effortless. Also, there are different ways to do it. Here are some of them:
1- Online Speed Tests
Online speed tests can quickly provide insights into bandwidth, packet loss, and latency issues. Here are some of the best online speed tests that you can use.
- Cloudfare’s Internet Speed Test: As soon as you visit this website, it will automatically test your internet speed. It displays download and upload speed, latency, and jitter.
- Ookla’s Speed Test: Probably the most popular speed test tool, Ookla displays your internet speed and ping. If your ping is high (>150ms), you will likely experience disruptions in call quality.
- Fusion Connect Speed Test Plus: Fusion Connect displays download & upload size, latency, and jitter. It also illustrates whether your connection is good or bad.
2- Terminal-Based Ping Tests
Online speed tests sometimes might provide a misleading view of your network connection. Here is how you can perform terminal-based ping tests.
Open your Command Prompt (Terminal for Mac users) and enter the command:
- Windows users (Command Prompt): ping -n 20 8.8.8.8 (Your IP Address)
- Mac users (Terminal): ping -c 20 8.8.8.8 (Your IP Address)
This command will send requests to the Google server with eight packets (the number “8” in the above command indicates the number of packets) and display something like this:
- Packets: Sent = 8, Received = 8, Lost = 0 (0% loss)
- Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 107ms, Average = 13ms
Take note of the average round trip time. In the above example, it is 13ms of jitter. Also, make sure that the packet loss is always zero (0).
3- Advanced Network Monitoring Tools
Large enterprises usually have access to robust network monitoring tools. These tools monitor your inbound and outbound traffic at the router level. As soon as they notice high jitter, packet loss, or low bandwidth, you will be alerted.
Here are some of the best network monitoring tools for businesses:
- LogicMonitor
- Cisco DNA
- Dynatrace
- Solarwinds Network Performance Monitor
How Jitter Affects VoIP Call Quality?
As mentioned above, VoIP call quality depends on how good your internet connection is. And, you are likely to experience high jitter during office hours.
High jitter means a delay in sending data packets. Think about it this way: if your speech reaches the recipient in a different order than it was sent, it will impact your conversation.
Let’s suppose you say, “Hi sir, I’m Eva from XYZ Company, how can I help you today.” Due to high jitter and inconsistent data packets, the customer hears:
Hi sir, XYZ company from I help you Eva today I’m how can or
Hi, I’m Eva, how help you today (in the case of packet loss, some words might be missing).
The above sentences don’t make any sense. And, when a customer hears it from you, it won’t be a good experience.
Acceptable Jitter for VoIP
It is worth mentioning that all internet connections have some network jitter – it is normal. But, when it is high, it will affect your VoIP call quality.
According to Cisco, the average one-way jitter should not exceed 30ms. Also, make sure your packet loss does not exceed one percent (we tested packet loss in terminal-based ping tests).
When it comes to latency for VoIP, one-way (mouth-to-ear) transmission delay should not exceed 150ms and the round trip delay should not exceed 300ms.
How To Fix Jitter Issues?
Now that you have tested your network jitter, it’s time to troubleshoot and reduce jitter. The first step is to ensure your existing network equipment is up-to-date and of high quality.
You can then try these solutions to fix jitter issues:
1- Use a Wired Connection
Wired connections are always faster than wireless connections. Besides, they are vulnerable to interference from microwaves and electrical motors. Additionally, consider upgrading your ethernet cables to Category 6 cabling to rule out defective wiring.
2- Deploy Jitter Buffer
If you are experiencing jitter issues consistently, you can deploy a jitter buffer. It delays VoIP audio enough to reorder voice packets correctly. However, it is essential to set up a jitter buffer properly.
Too much buffer and your voice will take longer to reach the recipient. Too low of a buffer, and you might experience increased packet loss. Therefore, it is recommended to set a buffer under 200 milliseconds.
3- Enable QoS (Quality of Service)
Many times, the network gets saturated with non-voice traffic (e.g., downloading huge files, large data transfers, etc.). This can limit your access to VoIP networks, thereby affecting the call quality.
Here are two ways to enable QoS:
- Schedule non-voice activities outside of business hours.
- Install an additional internet connection to handle VoIP calls.
4- Upgrade Your Internet Connection
If all the above tactics fail, upgrade your internet connection. Choose a fiber-optic connection for lower latency. Also, make sure you get a substantial upload and download speed that is capable of handling VoIP calls.
Wrapping Up
VoIP is an extremely powerful business phone system, owing to its rich features at an affordable price. However, network issues like jitter can hamper your call quality. If so, use the four strategies mentioned above to diagnose jitter issues to enjoy a high call quality all the time.
Have you ever faced jitter issues on your VoIP network? What did you do to diagnose the problem? Let us know in the comments.
Updated : October 25, 2024
Rohit Rajpal is a technical content writer with hands-on experience in the VoIP and telephony space. His expertise comes from closely collaborating with product teams to craft clear, technical documentation and user guides for telecommunication software. Rohit’s deep knowledge of VoIP technology allows him to address complex technical issues and provide insightful solutions.
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