VoIP Quality


VoIP (or Voice over Internet Protocol) phone systems have been around since around 2000. The technology is quite mature and as long as it is set up correctly has better call quality than the analogue phone lines it typically replaces. Unfortunately it is not always been set up properly and has unfortunately resulted in many horror stories of calls breaking up and intermittent service. Some clients I have dealt with have such a bad experience that they are extremely reticent to consider using VoIP when putting a new phone system.

The Problem

There are several factors that have lead to VoIP receiving a bad rap for use within businesses, particularly small businesses.

  1. Internet connection: The quality of VoIP is very dependant on the quality (not speed – but “jitter” and “packet loss“) of the internet connection. A poor (and often cheap) internet connection will result poor quality calls. Internet quality has been very variable over the last 10 years, slowly improving over time. In the early days of VoIP this lead to many quality issues that no longer exist.
  2. Cost vs Quality: VoIP was originally marketed (particularly to consumers and small business) as a way to reduce your phone bill. Cost was the big driver, so there was a big push to use cheaper internet connections, cheaper hardware etc. This all affected the quality of the phone calls.
  3. Lack of experience: Until recently there was very little cross over between IT companies (who looked after computers and internet) and Phone System companies (who looked after phone systems). They used separate cables within the office, separate lines into the office and totally different technology. Unfortunately VoIP systems need engineers and technicians who are familiar with both arms – it is still rare to find them. So IT companies will install a phone system like they are computers and wonder why the calls break up whenever someone is using the internet heavily, conversely the phone system company don’t understand the intricacies of the data protocols (SIP) and networking leading to poor quality or unreliability.

However all these problems are due to the implementation of the technology, not the technology itself. When cars were first introduced at the turn of the last century, they were expensive, broke down often, didn’t go very fast, were smelly and noisy – however this was no reflection on the capabilities of the internal combustion engine (despite many at the time dismissing the idea that they would ever replace the horse and carriage) – just the way it had been implemented at the time. Indeed it took a revolution in the road network before cars really took off.

We are at a similar juncture with the evolution of VoIP. With the introduction of the NBN, finally there is a network that can easily carry VoIP traffic and carry it with high quality – indeed it will only carry VoIP traffic, not the traditional phone calls delivered over the copper line.

The big advantage of VoIP is that typically the systems that use it provide many more features than traditional phone systems. Features such as call forwarding, individual voicemail, call conferencing, multiple lines per extension, phone directories etc. Since we are now in the world of computers there are possibilities of integrating IT systems with phones such as automatic call logging with Customer Relationship Management (CRM) systems.

How it works

The big difference with VoIP systems is that unlike the traditional phone network where your phone provider brought the cable to your door and was responsible for everything up to your door (call delivery, call quality etc), there are multiple parts and providers involved.

  1. The handset on your desk. It is important that this is a high quality handset that will convert the audio signal into the data signal over the local network.
  2. The local network. If the network is shared between the phones and the computers, any congestion here (due to transferring files from one computer to another) can lead to call quality issues.
  3. The local phone system. If you are using a hosted phone system, then this will not exist. It is generally better if the phone system talks the standard VoIP protocols (SIP & RTP) natively – some older or proprietary phone systems will need to convert to the standard VoIP protocols – this conversion process is not always perfect.
  4. Gateway router. Normally your internet (or data) connection runs significantly slower than your internal network. This will cause data to be queued at your main router. VoIP data is very urgent (any significant delays in the data delivery causes calls to break up). In extreme situations the queue can exceed the capabilities of the router and any extra data is lost. It is therefore important that the gateway router implement Quality of Service (QoS). QoS allows the router to detect VoIP data and effectively put it to the head of the queue for transmission.
  5. Internet connection. A poor quality internet connection will lead to poor quality calls. Many internet providers do not design their networks for VoIP, just for general data. There can be congestion in the internet providers network, leading to the same data delays (jitter) and even packet loss.
  6. SIP Trunk. This is the far end of the internet link, where the calls are put back on the regular telephone network to complete the call. A SIP Trunk provider uses complex equipment to perform this conversion, some providers can suffer from congestion on their network or use poor quality equipment.

Because of the possibility of “buck-passing” (where one provider blames another in the above chain for quality issues), there are great benefits to using a single provider for the entire chain. This will give you a single point of contact and responsibility even if the provider subcontracts part of it (which is highly likely).

Article Name
VoIP Quality
VoIP has had very variable network quality over the last 10 years. If implemented properly over high quality networks, it has the capability to deliver higher quality calls than the traditional phones it is replacing.