VoIP call quality & where to host your PBX – some basic considerations

If you are looking to upgrade your business telephone system, you should consider a Voice-over-IP (VoIP) system. VoIP not only allows you to make calls over the internet but it lets you manage the phone calling experience in ways previously inconceivable.

For VoIP, you will need an IP PBX (i.e. Internet Protocol Private Branch Exchange), which is the system that allows you to route & manage calls. The PBX also connects to a SIP trunk…the protocol that lets you send & receive phone calls over the internet. Whereas in the past a PBX was a piece of hardware, today there are many PBX solutions that are entirely software-based (‘virtual PBX’). Whether hardware or software-based, you will need to decide where to host, that is, where to locate your PBX.

Why does this matter? One of the reasons hosting matters is call quality. The distance between your phones and your PBX is one of the major determinants of the sound quality of your phone calls.

There are basically three options for hosting your PBX:

  1. on-premise
  2. off-premise at a known location/address
  3. off-premise in the cloud

On-premise PBX

Companies that store their PBX in their office premises don’t need to consider connecting their phones to their PBX over the internet. They therefore avoid one of the factors that might negatively influence the quality of phone calls.

However there are a number of disadvantages to hosting on-premise:

  1. Firstly, you need to provide the physical space and infrastructure for the PBX, potentially include server, rack, wiring, etc.
  2. Secondly, if you have more than one branch or site, you will need to invest in one PBX for every site you have.
  3. Thirdly, if your internet or electricity ever fails, your PBX will also not work and inbound calls will not reach you.
  4. Fourth, hosting on-premise implies that your company owns the PBX. Some companies prefer such an ownership model. Others prefer not to own as you need to make an upfront capital investment for hardware, software, space, wiring, as well as maintenance & updates.
  5. Finally, someone in your IT team would need to look after the system configuration & maintenance, i.e. you need to hire or train in-house expertise.

Most of these challenges can be solved by opting for a solution hosted offsite. You can host your PBX at a specific known location (for example, a data centre) or in the cloud.

Cloud Hosting

Outsourcing your VoIP telephony service to a managed VoIP service provider has many benefits such as

  • very low or even zero set-up costs,
  • predictable monthly service costs,
  • no update/maintenance hassles, expert customer service and
  • easy scaling/expansion.

However, often when the term ‘cloud’ is used, the service provider won’t or cannot disclose exactly where your hard-or software will be hosted. Many international VoIP communications providers host client systems across the globe in preferred data centre hubs. The physical distance between these hubs and your office can have a significant effect on call quality.

For example, hosting a PBX in Europe, with your office located in Thailand, is a virtual guarantee for poor & interrupted call quality. Therefore, if you consider a cloud solution, ask your provider where the PBX is hosted and how they will guarantee high quality. Then, test the solution extensively before you sign.

Off-premise Hosting at a Known Location

Some VoIP providers, especially local providers, host the PBX locally, that is, in the same, city, region or country of where your offices and phones are located. Often they rent rack and server space at a local data centre, as this provides the best convenience, security and quality of service. Data centres connect to a range of internet service providers, so you can choose the one with the most reputable internet service quality.

Going for a locally hosted managed VoIP service brings you all the benefits of a managed service (‘Telephony-as-a-Service’ or ‘TaaS’) but avoids the poor quality pitfalls of cloud services that are hosted far away.

Other Quality Considerations

Naturally, there are many other factors other than PBX hosting that contribute to call quality. A competent VoIP service provider should understand & give expert advice on how to optimize the technical aspects that avoid jitter & latency for example.

While you no longer need large internet bandwidth for making quality VoIP calls, a stable internet service and optimized QoS- and firewall settings are required, as well as high-quality desktop phones or headset devices to make calls.


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