How much bandwidth do we need for IP telephony and remote working?

March 15, 2022 Alex Dunlop

The PSTN 2025 switch-off means the writing is on the wall, for traditional PSTN-based lines and telephony. 

As a result, you will need to move away from your traditional phone lines and embrace Voice over IP (VoIP). 

Let's consider what this transition looks like for companies like yours, by exploring how much bandwidth you'll need. But first, we'll address a potential concern, as well as looking at the perks of moving. 

What about reliability...and what are the benefits? 

For some, there may be worries around the resiliency of their communications once they move to VoIP. After all, if calls go over the internet and the internet goes down, you lose your calls as well, right? 

However, UK internet connectivity has proven to be very reliable in recent years. Notably, even in 2020 when usage doubled due to the pandemic, OpenReach still managed demand, with no major outages that year. 

Crucially, the shift to VoIP will come with some compelling benefits compared to a standard phone line. These include increased flexibility and reduced costs. 

It's also important to note that for other technologies that rely on the PSTN, such as alarms and monitoring systems, you have the opportunity to move to a 4G Data Sim rather than traditional broadband. Once you understand what bandwidth you need for these technologies (this will vary per device and your usage), you can decide on the right approach. 

OK, and how much bandwidth will we need for VoIP? 

Naturally, you'll need more bandwidth when you go to VoIP, and how much more will vary depending on your average usage. 

For voice calls going over the internet, 100kbps is a rule of thumb. 

Video calls will end up eating up a lot more bandwidth, and here the numbers will vary more. 

  • High definition, 1080p resolution, means you can expect to see four standard definitions of 480p come in at 1mbps to 5mbps.
  • 4k will be around 20mbps. 

To assess your bandwidth needs, you'll need to work out the number of concurrent calls (or voice calls) your users have, and then multiply it by the relevant bytes per second for that format. 

For example, if you have five people using VoIP at one time, that becomes 500kbps. 

However, this is complicated by aspects such as how much actual 'functional' bandwidth you have or can get, as this will vary from what you signed up for with your broadband provider. Remember you will also want to add a safety margin in case there are issues, which means signing up to a bandwidth that is a little higher than what you think you need 

Ultimately, unless your needs are straightforward, you'll want to get outside help to land on a definite number. 

Meeting your bandwidth needs 

Without enough bandwidth, your staff won't be able to use VoIP and video calling effectively and may run into quality and performance issues that will impact their day-to-day work.  

Fortunately, you can find out your bandwidth needs by working back from the average amount of time your staff spends on calls currently, and by getting help from experienced experts. 

If you would like Claranet’s help in updating your technology to meet your requirements, please reach out today. 

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