The following are examples of problems with audio quality.

• Echo
• Choppy
• Buzzing / Static / Interference
• Beeping or Tones
• Delayed Speech or Dead Air

Echo

Echo can occur when voice traveling out from the earpiece or speaker makes its way back into the mouthpiece or receiver. This is known as acoustic echo. Turning down the volume on the phone can aid or reduce echo. 

Echo can also be caused by electromagnetic interference. It is recommended to position IADs/ATAs or base stations away from computers, the back of monitors, and/or power strips as these devices have large electrical fields. Poor wiring, long lengths of untwisted cabling (wire), wet or damaged cable and poorly terminated cables will also cause echo and crosstalk.

Here are some recommended solutions:

• Cover the mouthpiece to see if that reduces or eliminates the echo. If this helped, then turn down the volume on the phone.
• Move IADs/ATAs away from electrial devices.
• Remove splitters between IADs/ATAs and the phone.
• Try replacing cables which may be damaged or are poor quality.
• If using cordless phones with an IAD/ATA, try a corded phone to see if the echo is eliminated. 

Choppy

Choppy or broken audio on a call is usually an issue with insufficient or unavailable bandwidth. There can be many reasons why bandwidth is either insufficient or unavailable. We recommend running our VoIP Quality Test for two days or 48 hours. This will provide us with information that will help us identify what might be causing the choppy audio that can then lead to a solution.

Here are some recommended solutions:

• Reboot ISP modem (This will bring down all internet services. Depending on the device, it could take at least 3-10 minutes.).
• If there is a computer or device downloading/uploading large files, or streaming, try stopping the computer or device.
• Check QoS settings. If there are no QoS settings, we recommend using a Mikrotik that allows for QoS (this involves bridging the modem).
• Test bandwidth for known speeds. if speeds are not at expected levels, it may be necessary to open a trouble ticket with the ISP. To test your bandwidth, you may use our Capacity Speed Test. Please note, for best results, run the test without any downloads/uploads or streaming on the network or connection being tested. Also note that even though speeds may be fast, that does not account for packet loss, which will cause choppy audio.

Buzzing / Static / Interference

Buzzing, static, or interference can be caused by the introduction of a signal or voltage into the connection. If using an ATA, it is best to test with a corded phone with the ATA to see if the buzzing/static/interference is fixed. Cordless phones can generate static if the signal is weak. Cordless phones are also susceptible to interference from other wireless devices.

Here are some recommended solutions:

• Replace bad power adapter. Using an incorrect power supply that has different voltage can cause problems.
• Try plugging in the power adapter to a different 110volt source.
• Try a different ATA and/or phone.

Beeping or Tones

Delayed Speech or Dead Air

Delayed Speech or Dead Air is usually caused by packet loss, latency, jitter, or packet discards. So if there are bandwidth or connection problems, that will cause delayed speech or dead air. Sometimes there are other facotrs that can cause delayed speech or dead air. The following will cause such problems:

• SIP ALG
• Double NAT-ing
• Forwarded calls from another carrier

SIP ALG or Application Layer Gateway is common in most commercial routers and it is supposed to help prevent problems caused by router firewalls. Many routers have SIP ALG turned on by default. Even though it was intended to help, SIP ALG causes problems because it modifies SIP packets and can malform them and become unreadable or corrupt. Add muliple IP phones and other network traffic and the problem increases. It is for this reason that we strongly recommend disabling SIP ALG when it is active. To do so, the user must contact their ISP which usually is the only one that can manage their modem/router. Since, the ISP is usually the only one that can manage the modem/router, it also recommend that they bridge the modem so that another device that can be managed and access do the routing. We recommend using a Mikrotik which is a great router, is SIP friendly, allows for QoS, and gives both partners and us control.

Double NAT-ing is when a router providing a private LAN has another router with a private LAN behind the first router. NAT or Network Address Translation works with VoIP, but when adding a second layer of NAT, it will cause havok with how the traffic is sent to the IP Phones. This is because NAT not only handles the private address, but also the ports that is needed for the device to communicate which the second layer of NAT will break. For this reason, we recommend that IP phones only be on a single NAT enviornment.

The other reason that could cause delayed speech or dead air, is receiving a forwarded call from another carrier. Since we cannot control what is being sent to us in the forwarded call, there is little that can be done about this issue. This occurs when forwarding numbers to temporary aliases that are receiving calls until numbers are ported. Once the numbers have been ported, these issues are usually resolved.