Identifying the Problem: Dropped Calls

A dropped call is a call that ends before you intentionally disconnect. You may hear a fast-busy signal or no sound at all. Troubleshooting this problem is difficult given the number possibilities involved. The issue could originate in your device, your local network, or your connection to the Internet.

If you’re not losing the whole call, just portions of the conversation are dropping out, see packet loss below.

Potential Causes of Dropped Calls

Do you get a fast-busy signal?

If the dropped call goes immediately to a fast-busy signal, it could be:

• another device on your local network taking control of the line or introducing interference.
• a problem with the signaling between two IP phone systems.
• a firewall configuration issue.

Does the Dropped Call Result in Silence?

If the dropped call results in silence, however, it may be due to heavy traffic on your Internet connection.

Does the Dropped Call Eventually Come Back?

If you stay on the line and the call eventually comes back, you can be confident that latency is the problem, see below. Heavy traffic on your Internet connection has pushed the call data to the back of the queue.

Solutions to Fix VoIP Networks Dropping Calls

One way to reduce dropped calls is to use a “soft phone” rather than a physical one. Computer and smart phone applications such as Skype, Zoom, and Google Hangouts use smarter codecs that do much better at working around network difficulties. Everyone on the call needs to be using the same application, which is a disadvantage.

Adding bandwidth can resolve dropped calls—at least until your Internet traffic volumes increase again.

Or get InSpeed to solve dropped calls once and for all.

Identifying the Problem: One-Way Audio

One-way audio occurs when only one party can hear the other. The connection is good, so you have to figure out what’s preventing the sound from reaching the party who can’t hear.

Causes for One-Way Audio in VoIP Calls

First, check to make sure that the desk phone or softphone that’s experiencing the issue is working properly.

If you eliminate the possibility of a faulty phone, the issue is probably due to:

• network address translation (NAT) or
• firewall settings that block traffic from the Internet.

Fixing One-Way Audio

1. Simplify the connection by plugging the phone directly into the router and make a test call.
2. If you still get one-way audio, determine if the router is giving the phone a public or private IP address.
3. If it’s a public IP address, the problem is with your VoIP provider.
4. If it’s a private IP address, disable DHCP on the router or configure your router to enable port forwarding.

Identifying the Problem: Choppy Calls, Jitter and the Robot

Choppy calls are one of the most common VoIP quality issues. They are the result of jitter, which technically refers to the variability of latency across transmissions. In layman’s terms that simply means that voice data packets arrive out of order because they followed different paths and/or experienced differences in delays.

Jitter occurs due to inadequate bandwidth or a lack of prioritization of voice data packets.

Muffled Voice and Robot Voice

Both muffled voice and robot voice are symptoms of packet loss concealment.

Robot voice can happen in any audio device (phone/softphone/computer/smart phone) dealing with packet loss and repeating packets to replace the lost packets.

On some devices the voice is muffled, such that it is so soft it can be difficult to understand. This is the same problem as robot voice, handled differently by the device. Soft volume is dealing with a low rate of packet loss and the device is turning the gain (volume) down in hopes the listener won’t notice the device’s attempt to cover up the loss.

Fixing Jitter (Choppy Calls)

• Adding bandwidth may or may not resolve this problem. One way to do this is to have additional routers, as this will increase the data packet transfer rate that may be slowing  your network.
• Another way to add bandwidth is to get a gaming router.
• One trick for fixing jitter is to use a cloud service, then make your phone calls using a VoIP app on a smart phone. You’ll want to use Wi-Fi for the smart phone calls, which means you may need to upgrade your Wi-Fi router to one that handles voice.
• An MPLS link will provide prioritization for VoIP traffic, but that can be expensive. MPLS is more than 100 times as costly per bit than the public Internet.
• We humbly suggest InSpeed QoS can ensure that interactive applications such as VoIP and UC are given priority over other data transmissions.

Identifying the Problem: Echo and Latency

Echo is caused by latency. VoIP data packets are delayed, causing you to hear the sound of your voice repeated after you’ve spoken. Latency occurs even in traditional phone connections because of the time it takes for the sound to physically move from the phone across various networks and switching systems and to reach the phone on the other end. However, it’s seldom noticeable because of the extremely low latency of traditional telephone networks.

With VoIP, echo can be very noticeable due to the extended delays that often occur when packets travel over the Internet. Once latency reaches 300 milliseconds, call quality has noticeably degraded.

Note that echo can also be caused by sound coming out of the speaker looping back and coming in the microphone from the far end. In the old telephony world, the delay was short—less than 50 ms—so the caller rarely noticed. In VoIP the delay is longer and as it approaches 150ms the echo becomes a nuisance.

How to Improve Latency

AKA Getting Rid of Echo in VoIP Calls

If your echo is simply a feedback loop from multiple devices in the room with microphones, simply turn off one of the mics or devices. Otherwise, use a soft phone as its codec may have a better echo canceller.

For latency, there are echo cancellation settings and add-on devices that can help reduce the problem. You may be able to buy a specialized router that will set aside bandwidth for particular uses or applications. An IT professional can adjust your TCP/IP protocol settings, which will be depend on the particular bandwidth traffic issues in your business. Just like the traffic on the freeway, your bandwidth will have particular traffic patterns but will also change based on your particular network and use.

Keep in mind Quality of Service disappears the moment it enters your modem. Using InSpeed will eliminate echo by prioritizing VoIP data packets over the Internet. It’s a dynamic solution, because your network traffic is always changing.  Just get InSpeed and be done with it.

Identifying Causes of Static in VoIP Calls

Static or buzzing on VoIP calls is typically related to electromagnetic interference. This could be caused by the use of the wrong type of power supply, a nearby device that’s introducing electrical voltage, or wireless devices that broadcast on a similar frequency as your phone. Sometimes nearby cell phones create interference.

Handsets on desk phones can create hum. Switch it with another handset in the office. Guess what? Even if there’s nothing wrong with the handset, the problem will frequently go away. Look out for the placebo effect in solving VoIP static!

Fixing Static on VoIP Calls

1. For cell phones, move into a different environment in case you are experiencing interference.
2. Do a test call in another area that has no electronics humming.
3. Check that your power supply provides the correct voltage and amperage, and eliminate any devices that may be causing interference.

Identifying Causes of Packet Loss

The human ear is pretty good at filling in very short gaps, but even small amounts of packet loss will degrade the quality of the phone call.

Packet loss is the culprit when portions of the phone call get dropped. Packet loss is the culprit when portions of the phone call get dropped. Packet loss can be due to:

• Transmission errors
• Network congestion
• Lack of voice packet prioritization

These days, packet loss is mainly caused by congestion; the network itself rarely drops even a single packet.

Fixing Packet Loss

Limit your time on congested networks. Many SD-WAN products employ a second connection, automatically avoiding the congested network that introduces packet loss.

• A small branch office can buy a specialized router that reserves bandwidth for particular users and particular applications, such as gaming. It’s a bit crude but it can be configured to send voice packets out first and throttle TCP traffic.
• An MPLS link will minimize packet loss, but that’s an expensive solution.
• With InSpeed QoS you can eliminate packet loss over any WAN, with a single connection. InSpeed’s service creates an overlay network on any network connection which then honors packet priorities. The overlay is created between the InSpeed premise device and InSpeed virtual devices in the cloud. Rather than relying on packet markings, InSpeed uses a variety of proprietary techniques to maintain quality: latency, jitter, and loss.