Increased quality
Advances in compression and low-cost digital signal processors (DSPs) have provided the main methods of improving quality. Such technologies can also reduce the bandwidth needed to carry voice traffic Ã,Âanother big advantage of VoIP.
The standardisation of quality of service (QoS) protocols has also brought benefits for organisations, enabling the latest generation of switches to allocate guaranteed bandwidth to particular types of traffic Ã,Âprioritising traffic from particular sources, for example. But there are still many concerns about quality, particularly for long-distance calls involving the Internet.
However, VoIP vendors and service providers are constantly improving their tools and infrastructures to improve transmission rates.
Firms can use VoIP for internal deployment to enable voice and data to be carried over traditional copper lines, whether in a single building, or between locations and out to branch offices. IP-based PBXs are readily available from a number of vendors, and can typically support a mix of PCs equipped with audio cards, IP-enabled phones and, in many cases, ordinary analogue handsets. Many vendors can also provide the gateway necessary to interface to the analogue public phone network.
However, most companies currently considering IP-based PBX equipment will want to completely replace an analogue system or equip a new building from scratch Ã, because it is much harder to justify the installation and upgrade costs if adequate analogue facilities are already in place. The lure of some other benefits, such as the ability to build integrated voice and data applications, may well change that, but it may still be some time before VoIP becomes a first choice for many firms. That said, some analysts predict that by 2005 up to a third of corporate voice traffic will be carried over IP connections.
Internet service providers initially saw VoIP as a way of competing against the PSTN network providers, such as BT in the UK. But the telecoms providers have not been idle and have countered with VoIP services of their own. Most of these VoIP services are aimed primarily at corporate customers and there has been a slew of announcements of late. Most are currently pilot schemes, and firms such as BT are wary of stealing custom away from their very profitable PSTN businesses.
Despite the technical advances and the ready availability of products, VoIP is still an emerging technology. Solutions for in-house deployment are maturing rapidly, but a lot of work needs to be done before IP-based telephony can fully rival the PSTN alternative, particularly for long-distance calls. The full benefits of VoIP have not yet been realised.
