The continued shift from legacy circuit-switched networks to packet-switched networks has resulted in the rapid growth in the use of Voice over Internet Protocol (VoIP) and it’s estimated the number of global corporate VoIP users will rise to 205 billion by 2020, accounting for annual revenue of $86 billion.
VoIP technology innovation has meant equipment costs are lower and companies can spend a lot less for long distance, international and mobile roaming calls. It’s also easier to install, configure and maintain and can scale, up or down, to cope with changing business requirements.
But despite these benefits, VoIP isn’t without problems.
Quality of service (QoS)
Although problems are much less of a concern than they used to be, there’s a variety of underlying problems that can ruin the user experience through dropped or jittery calls, one-way audio or echo.
- Legacy network equipment – routers, firewalls or other equipment that is underpowered and hasn’t kept pace with business growth is one of the main causes for poor VoIP quality. The problem can be exacerbated if the original IP network assumed light voice traffic but now needs to cope with video, which will consume a lot more bandwidth.
- An unplanned increase in the number of voice calls – having implemented VoIP for one or two departments and seen the advantages, the company might then extend its use, but quickly hit capacity constraints.
- Wrong codec – the network vendor will likely make the choice, but if it’s incompatible with other hardware and software being used by the company, it could impact quality.
- Congested networks – can cause routers to drop packets resulting in gaps in speech, or if packets are received in the wrong order, jittery audio.
How to maximize QoS for your VoIP service
QoS is the number one requirement when planning a VoIP implementation.
For some companies, running a separate network for VoIP is the way to go, but for others the cost is prohibitive, and they need to find a way of improving QoS on a network shared with data traffic.
Scoring techniques can create a baseline against which improvements can be measured and, depending on the problems being experienced, there are different solutions that can be used.
Differentiated services: vendors like Edgewater Networks have QoS configuration features built into their routers which means traffic like VoIP can be prioritized on each port.
Congestion avoidance: VoIP packets are marked with headers identifying them as high-priority traffic and congestion management tools monitor network traffic to find and drop low priority packets.
Jitter buffer: jitter can be avoided by using a buffer that delays incoming packets and validates their order before use, although the delay has to be setup properly to prevent it from impacting call quality.
Software defined wide area network: SD-WANs have QoS features, such as forward error correction to re-create missing packets, included in their design by default and are increasingly becoming a favoured choice for VoIP use. And despite the name that suggests it’s only suitable for a large enterprise operating sites over a wide area network, it’s actually a cost-effective solution for businesses of different sizes.
Hosted VoIP: a hosted VoIP service is attractive to SMBs because of its flexibility. Support for more, or less, users can be provisioned remotely meaning you only pay for what you need, and maintenance and regular upgrades are provided by the service provider and factored into the annual charge. It also pushes responsibility for service reliability and quality onto the service provider.
Professional services: network vendors can help address any problems found with VoIP networks and are the best option for smaller companies with little or no technical resources.
Looking forward, 5G is set to give VoIP another revenue kicker by realizing the potential of mobile business VoIP. And since latency for 5G is less than one millisecond, it comes with huge improvements in call quality.