VoIP is probably the least understood telecom subject – even among dealers. So – here is a quick primer to get you up to speed.
Today, commercially available VoIP comes in five (5) basic flavors:
1. VoIP Dial Tone
2. VoIP SIP Trunking
3. VoIP PBX Gateways
4. VoIP Extension Phones
5. VoIP to the PC
VoIP Dial Tone:
This is what most people mean when they say “Does this phone system support VoIP?” Companies like Vonage, Packet-8 and Lingo offer VoIP phone service that competes with local and long distance phone companies. They will gladly tell you that their service is not usually dependent on what type of PBX you use, but you have to ask. In fact, you could hook up a $10 single line telephone to their service and it would work.
To the PBX, it’s just another POTS line (Plain Old Telephone Service). There are many companies that claim to have a new PBX that work with these VoIP lines and suggest that you switch over to their hardware. Unfortunately, they fail to tell you that it is totally unnecessary since these circuits will work with any phone system or any single line telephone. Before they get connected to your PBX or home telephone, they have been converted to look like regular analog lines.
VoIP SIP Trunking:
SIP Trunking is Dial Tone that is obtained from an ITSP (Internet Telephony Service Provider). Instead of breaking the circuit out into analog channels, it stays digitally packetized from the ITSP’s Central Office to your equipment. SIP Trunking is obtained using a broadband Internet connection that plugs into your PBX. Typically, each voice channel (also referred to as a ‘session’) requires between 60k and 85k of bandwidth, depending on the codec employed. SIP is an acronym for Session Initiation Protocol.
The service is usually sold through Telephone Equipment Vendors such as KX-TD.COM because of the initial complexities of its one-time setup. This is fairly new technology and it is rapidly growing in popularity due to the low monthly costs. Currently, Panasonic supports SIP Trunking on all of their KX-TDE IP PBX’s, all of their KX-NCP Series IP Converged PBX’s and the new KX-TDA50G. SIP WILL be the dominant technology going forward.
VoIP PBX Gateways:
These are essentially “H.323 Tie Lines” between PBX systems. An example of this would be a company that has multiple locations and the desire to connect them together to achieve free intercom calling. There are several ways to do this from something as simple as D-to-A Converters (FXO & FXS Cards) in your router. Most advanced IP PBX’s actually allow you to install special VoIP Gateway cards, which in turn connect across the Internet to other PBX’s with the same card to create Tie Lines.
The advantage to this is that it sends other call information, such as the extension name and number, lamp information, distinctive ringing, etc. through the gateway. For added security, VoIP Gateways from Panasonic operate within a VPN (Virtual Private Network) or across Frame Relay Network. Panasonic KX-TDA, KX-TDE and KX-NCP Series systems all have this option.
VoIP Extension Phones:
VoIP Extension Phones are becoming very popular. Today, there are three (3) types of VoIP Extension Phones, (i) Single Line Analog sets, (ii) Fully Integrate Multi-button Key Sets and (iii) Soft Phones. Single Line Analog sets are also called “dumb phones” since they do not digitally pass information between the phone and the PBX. These are like the old fashion phones that we all had in our homes in the 70’s & 80’s. Fully Integrated Multi-button Key Sets are “smart.” They look and act exactly like your wired desk set.
The difference is that the wired desk set is near the PBX and the VoIP Phones can be half way around the world. Instead of a wire, they use the Internet, along with some sophisticated built-in software to make the connection. Panasonic remote IP Phone users can access every feature that a wired phone user can. For added security, VoIP Gateways from Panasonic operate within a Hardware VPN (Virtual Private Network) or across Frame Relay Network.
Soft Phones are communication software applications that appear on a PC or laptop screen as PBX extensions. Soft Phones typically operate in a less secure environment, such as a Software VPN or no VPN at all. Panasonic KX-TDA, KX-TDE and KX-NCP Series systems all have fully integrated multi-button IP phone options and the ability to use Soft Phones.
VoIP to the PC:
VoIP to the PC technology relies on processing power from a Personal Computer or other external processor. Unless you are willing to dedicate a PC for each conversation, this is not a wise choice (yet). VoIP to the PC would be services such as Skype. Skype is in the process of Beta Testing their SIP product with several PBX systems, including Panasonic PBX systems. This is an emerging technology and has some merit – especially internationally.
We will continue to keep an eye on these developments and when Skype has demonstrated that they can adapt to the needs of commercial users, we will reclassify them as a VoIP SIP Trunking product. There are other more gimmicky companies in the VoIP to the PC category such as Magic Jack. We do not consider Magic Jack to be a viable product for anyone.