Settling the great VoIP Debate

The argument for using Voice over Internet Protocol (VoIP) as a cost-cutting tool in businesses has long been won. In many instances, VoIP has cut costs in organisations by up to 50%. For others, the experience with VoIP was less than satisfactory – particularly the quality of phone calls.

Rob Lith, Director of Connection Telecom (image: Connection Telecom)

Complaints of delays, interference from non-voice traffic on the network and poor quality of calls are not uncommon or invalid. 

“But before one dismisses the technology, it’s important to examine both the reasons for these issues and the possible solutions,” says Rob Lith, Director of Connection Telecom.

A company’s Internet connection and bandwidth will always top the list of factors affecting voice quality in VoIP conversations. A broadband connection will work well as long as it is not ‘bursty’, does not suffer high latency and is not shared with too many other communication applications. However, this is not the only possible cause for poor call quality:

It could be your hardware

The VoIP hardware equipment used can greatly affect your voice quality. The cheapest solutions are normally the poorest quality (but not always). It is always advisable to have as much information as possible on an analogue telephone adapter, router or IP phone before investing in it and starting to use it. Bargain basement shopping for VoIP equipment is certain to end in disaster.

It could be your provider

Similarly, it is important to partner with the right VoIP provider. Experienced VoIP providers can employ a range of tactics to offer quality assurance, from infrastructural interventions including local area network (LAN) design and analysis, to managed interventions including monitoring of the solution, to a range of network applications to prevent and remedy quality issues. Of these, infrastructural preparation is the first and most fundamental.

You may have to upgrade

The IP-based access network of the enterprise must be adequately provisioned to handle voice, and also dedicated to voice traffic. Quite often, the access portion of the network will be a copper-based ADSL line. Unlike dedicated leased lines (Diginet circuits in South Africa), DSL offers only a ‘best-effort’ service. In such cases, the ADSL network over which the VoIP service runs must feature ‘un-contended’ (dedicated) capacity, provided in the form of ‘IP Connect’ capacity – a service from Telkom to VoIP providers.

But even in cases where IP Connect is in place, local ADSL exchanges may be over-subscribed. In such cases, no matter the quality assurance that has been implemented on the client’s side, VoIP traffic will suffer unless alternatives are sought to ADSL, or additional measures are taken to protect the voice traffic on it.

The alternative to ADSL in such a case is a leased line, which significantly increases cost for the sake of guaranteed quality. This will be off-set by the benefits of VoIP, which include call cost savings, infrastructure rationalisation and VoIP’s feature benefits of enabling collaboration, unified communications and business process integration. If this alternative is out of financial range for the customer, QoS can be pursued on ADSL in other ways.

The solution

A wide array of mechanisms is available to test for, enable and remediate VoIP quality.

A managed service, while not strictly speaking a quality-enhancing feature, can be effective in countering quality problems. VoIP providers should manage the entire service – from customer premises equipment through to the hosted PBX solution, if any.

VoIP call quality degrades quickly over low-bandwidth links, and lines can easily become over-subscribed. In countries such as South Africa, where bandwidth is at a premium, unchecked acquisition of more capacity will nullify the biggest benefit of VoIP – cost savings. Solutions that streamline traffic rather than drive up the cost of bandwidth are therefore in high demand. While compression can be one component to an overall solution, significant compression can also reduce call quality.


IP-based voice communication for business use has made aggressive strides forward while overcoming some of its past barriers and misconceptions. Today, VoIP technology coupled with a quality-of-service enabled network can provide businesses with enterprise-grade reliability and high-definition voice quality at a lower cost.

Rob Lith, Director of Connection Telecom