One confusing aspect of VoIP is the name itself. The term VoIP is an acronym for Voice over Internet Protocol. The thing that jumps right off the page at you is the term “Internet.” It immediately conjures up visions of broadband phone solutions that piggyback on top of Cable broadband or DSL connections. That is, indeed, VOICE going OVER the INTERNET. It’s also one example of VoIP. However, it is far from the complete story.
The idea behind broadband phone is that with the right equipment you can use your broadband Internet service to connect you to a competitive phone company. The whole impetus for this is that the local telephone company, called the ILEC for Incumbent Local Exchange Carrier, pretty much owns you for local phone service. It’s easy to switch long distance providers, but much harder to change local services. Why? Because the ILEC owns the copper wires between your location, business or residential, and the switching equipment in their office. You can’t dig up the wires and move them elsewhere, so you need an alternative “phone line.” The Internet provides just such an alternative connection.
One of the major pitfalls of broadband phone is that the Internet was designed for transporting data reliably, not for transmitting voice quickly. Everything on the Internet is transported in packets. That includes data bits representing digitized phone conversations, video clips, websites, email and many other things. What they have in common is a standardized packet structure called IP or Internet Protocol.
Now, here’s where the trouble comes in. The Internet treats one packet just like the next. It doesn’t matter if they are zipping along smoothly or all clogged up. The system is set up to get each packet from Point A to Point B sooner or later. Having data correct is much more important than having it as soon as possible. If a packet gets lost or corrupted, another protocol called TCP or Transmission Control Protocol sees that the packet never arrived at its destination and retransmits it. As a user, this is all invisible. All you know is that your email or web page displayed correctly.
Voice differs from data in that it is a real time protocol. A voice packet that shows up late is of no use because the conversation has already moved on. VoIP is set up to discard missing or out of sequence packets. A few here and there won’t make a difference, but a lot of missing packets will punch holes in the conversation and make it hard to understand.
Video is equally sensitive or even more so. The way video stays intact is to have the packets go to a staging area before they are displayed on the screen. This area is the buffer. Buffering collects packets however they come in and then feeds them out smoothly to create a continuous picture stream. Buffering also works for audio and is used for Internet radio stations extensively. That way any congestion on the net won’t cause the audio to drop out.
Buffering could be used for VoIP, but not very much or it will create havoc. The tradeoff is that phone conversations are two-way. The buffer will cause a big delay from the time you start talking until the other person hears it. Buffering and other delays show up as something called latency which turns two way conversations into more like walkie talkie conversations. Only one person can talk at a time and you have to wait before taking your turn.
What’s better? Bypass the Internet and use a private line connection called a SIP Trunk. SIP is the switching and signaling protocol for VoIP telephony. The SIP Trunk is carefully engineered to give voice packets priority over data packets and to have enough bandwidth to avoid congestion that causes latency and jitter.
SIP Trunks connect your company to your business VoIP service provider. The provider takes care of all outside lines to the public phone system. You can connect the PBX phone system you have now using a SIP Trunk or use an IP PBX that uses IP telephones rather than standard analog phones. Even more interesting is hosted VoIP, which eliminates the in-house PBX system completely. The service provider gives you both lower rates to use the public telephone system and takes care of switching both inside and outside calls.
As you can see, there are various flavors of VoIP phone service available today. You want to be careful to pick a solution that not only saves you money but has the features and voice quality you need to conduct business effectively. Enterprise VoIP providers have solutions for all size businesses at attractive prices. Compare features and costs now to discover what’s available for your particular locations.