It sounds like magic. With your VoIP phone, messenger or Skype ID and a suitable VoIP service, you can make phone calls over the Internet till the cows come home, and all at no extra cost. Underneath and all the time, complex technology is working hard to give you the best web phone service possible. However, VoIP communications don’t obey the same rules as traditional phone calls. This leads to differences in the way connections are set up, the sorts of communication that are possible and also the quality of those communications. Knowing a little about the obstacle course for setting up a VoIP conversation could help you get the best balance out of your conventional and your VoIP phone connections.
Everything is Digital – but Not Everything is Equal
Nowadays, much of all phone communication is essentially digital. It simply gets converted to analog at the end so that you can hear what’s being said. Vendors and telcos figured out years ago that they could offer more, charge more and use fewer resources by moving to bits and bytes. However, if you make a call on your conventional phone line, you are still guaranteed a fixed line capacity for the duration of your call. Apart from the standard ‘telephone effect’ on voices because only the mid-range sound frequencies are transmitted, the only other effect might be slight delay in speech (a small fraction of a second) for very long distance calls. VoIP calls on the other hand must contend not only with latency like this, but with additional challenges too.
Jitter and Packet Loss
To put it simply, where conventional phone connections have bandwidth for them alone, VoIP must share. VoIP conversations get chopped up into packets and bundled off with all the other Internet traffic packets like website interactions or streaming video clips. Because the Net may use different routes to send different packets, they may arrive out of order at the other end. In other words, part of what you said later could possibly arrive before a packet containing what you said earlier. If this happens for non-voice packets, then the time for the technology to figure things out and put packets back into the right order at the far end is often not noticeable. But for voice conversations that happen strictly in real time, out of sequence packets can cause an unpleasant jitter effect. Network congestion can have the same result. And sometimes voice packets may simply be lost – after all, that’s how the Internet works.
Just the Fax, Please
This packet-driven communication makes it harder to offer services like facsimile over VoIP. Fax machines may rely on the timing of certain signals to correctly initiate and transmit or receive information. Smarter new generation fax machines may get round this by having each packet contain data from the preceding packet. The net effect is then that it takes a loss of two packets rather than just one to have any negative effect on fax transmission over VoIP. Otherwise, you may prefer to use a mix of conventional and VoIP communications, at least until such time as such VoIP issues have been ironed out – or the world stops using fax and just sends digital files of scanned images.