Voice over Internet (VoIP) and Wide Area Network (WAN) are now ubiquitous. Many people nowadays, find it appropriate to use VoIP. Similarly, organisations find it necessary to use VoIP for cross-border calls as opposed to using traditional methods of communication. However, one important aspect about VoIP is the quality. As the use of the technology increases, it becomes necessary for service providers to ensure that they provide VoIP services of the highest possible quality.
Interestingly, measuring the quality of VoIP service offering is not as easy as it may sound. On the one hand, this is a relatively new technology that is still developing. On the other hand, we still have a long way to go before we can fully define the particular metrics suitable for measuring VoIP services. Here are a few metrics for VoIP and its related technology, WAN.
Jitter relates to the manner in which the voice packets that are sent in the course of a VoIP are received by the sender. In practice, the voice of the sender or the person who is calling is changed to packets of voice data. The packets are then transferred over the WAN to complete the VoIP call.
A problem occurs when the voice packets from the sender are received in an order that is different from that in which they were originally sent. When this happens, the receiver may experience low quality or scrambled audio in the course of the call.
Jittery is a relatively common problem in VoIP service offering. Hence, the extent to which users of a VoIP experience scrambled voice or noise is a good metric of determining the overall quality of the service. The importance of jittery as a metric of the quality of VoIP service arises from the fact that VoIP services do not introduce any kind of external noise to the calls. Therefore, service providers have to use particular methods to minimise the effect of the factors that cause jitter in VoIP services.
Latency is an important metric of VoIP and WANs. Latency refers to the time that it takes for the words that are uttered by the sender of a message to be perceived by the ear of the recipient. In practice, the human ear may not perceive delays in the delivery of speech within particular thresholds. However, when this threshold is exceeded, the human ear can perceive delays in the delivery of the voice. In this case, the speech from the sender sounds like an echo.
One of the major causes of latency in VoIP services is queuing delays. This form of delay occurs when the VoIP interface experiences a surge in outbound voice packets and it is forced to queue and deliver them later. Hence, the process of transferring the packets is staggered, resulting in delays in the delivery of the packets.
- Packet Loss
Packet Loss is common in VoIP services for one main reason: the protocols that ISPs use are not designed to handle voice packets. Hence VoIP services exert pressure on existing internet protocols, resulting in the loss of some of the voice packets that make up the VoIP calls. In practice, companies offering VoIP usually promise Packet Loss rates that are less than 1%, which is the industry standard.
In conclusion, latency, packet loss and jitter are the main metrics that can be used to determine the quality of VoIP over WAN. In practice, service providers improve their VoIP service offerings by implementing particular measures such the use of SD-WAN or Software Defined WAN and other traditional approaches such as prioritising and buffering.