The telecom industry has seen some real changes since the rise of the internet and widespread availability of broadband speed connections. One of the biggest changes is the number of people now using their internet service to make calls rather than the telephone. This technology is commonly referred to as VoIP (Voice over Internet Protocol). This form of making a call has been boosted by huge cost saving benefits, sometimes even being free. But it comes with its own issues, most noticeably call quality and connection issues. So for those who are thinking about using VoIP in the future, do the savings outway the quality?

How does VoIP work?

VoIP works but converting sound into data and sending it through the internet. The internet does not care what the data it carries represents. For instance, it makes no distinction between the data needed to read this web page and the data needed to carry a phone call. Data is simply data.

How does this affect things?

Now that you understand the way VoIP works you can appreciate that as the internet makes no guarantee about how quickly data is delivered, there are no guarantees that there won't be delays on the line.

The variable nature of the system explains what you may have already experienced in practice. Sometimes VoIP systems work well, sometimes they don't. It depends on the demand on the internet at that precise time.

It gets worse, here's why. VoIP services quite often use Transmission Control Protocol (TCP), a method of ensuring data is delivered reliably over the internet. The problem with using TCP is that it works by requesting that lost packets of data be retransmitted before data is presented to the receiver. This all takes time. With most data transfer, a short delay is preferable to receiving corrupted data.

Why VoIP calls are sometimes unclear and noisy

The problem with sending voice is that delays DO matter and matter a lot. It would be completely unacceptable to have to wait for a few seconds for your voice to be heard at the other end of the line. VoIP systems get around this problem by simply ignoring missing or corrupted data packets. When data is lost you experience it as 'pops' and noise or echoes on the line.

Traditional telephone (POTS) systems don't suffer from that problem.

Why this is particularly disruptive on audio conferences

When using VoIP for a one to one conversation between two parties you can put up with the odd noise on the line. However as soon as you get more than one or two callers on the line, the noise from each line is multiplied, becoming extremely disruptive.

Audio conferences held using traditional telephone systems do not suffer from this problem and therefore it's possible to hold crystal clear conferences with tens or even hundreds of participants.