If your business uses Voice over IP, then it’s useful to know how to troubleshoot and resolve the most common VoIP problems. Poor call quality is not necessarily your service provider’s fault, as there are many reasons why your local network or user devices could be causing problems like delay, jitter, packet loss and echo. So before you call tech support, run through this checklist to see if the issue can be easily resolved.
Echo can be introduced to a VoIP call in various ways. Acoustic echo usually occurs when the loudspeaker volume is too high, and the sound is picked up by the mouthpiece and retransmitted back down the line. Turning off the speakerphone, lowering the volume, or using headphones will normally resolve this problem. Echo may also be caused by electromagnetic interference if your VoIP device is placed too close to other electronic equipment such as a computer, cordless phone or power supply. Moving your device away from other hardware should resolve the problem. Finally, faulty wiring or poorly terminated cables may cause echo or crosstalk, so inspect your wiring and upgrade any old or faulty components.
Latency is the delay experienced between the time one party speaks and the other party hears their words. One reason for latency is propagation delay – i.e. the time taken for digital voice packets, transmitted in the form of light, to travel along fiber optic cables from source to destination. Latency is also introduced by devices along the network path that handle and forward the data. Finally, queuing delays can be introduced due to congestion on outbound interfaces, when more packets are transmitted than the interface can handle. The solution to latency is to prioritize voice traffic, minimize the number of devices along the network path, and reduce the geographic distance between calling and called parties.
Chopped Audio (Packet Loss)
Insufficient bandwidth can result in dropped VoIP packets, which leads to choppy audio. Congestion may occur on your internal network, on your Internet service provider’s network, or on the interface between those two networks. If the problem seems to occur at a specific time each day, then check whether your business is running other bandwidth-intensive applications at that time. Try testing the voice quality when all other computers are switched off, and run a bandwidth test (for example, speedtest.net) to verify your connection speed. Finally, you should ensure your router is configured to prioritize voice traffic – this is known as Quality of Service (QoS).
Chopped Audio (Jitter)
Jitter is a measure of the variability in the arrival time of voice packets across a network. Jitter is common on switched networks because each packet may follow a different path to the destination. Jitter buffers collect packets as they arrive and relay them to the receiver at a constant pace and in the correct order to ensure conversations are understandable. But if a packet arrives too late to be merged into the playback stream, then that packet will be dropped. If you are experiencing jitter then your jitter buffer may be incorrectly configured. A buffer that is too small will result in more dropped packets, while a buffer that is too large will result in excessive latency.
External Party Issues
If you’re experiencing quality issues with calls to or from external parties, then the far-end equipment may be the source of the problem. The external party may have an incorrectly configured network, or may be using a low-quality handset or a cell phone with poor coverage. To confirm if this is the case, ask the other party to try using an alternative device.