PhoneGod Interview Series

Actor, Comic, Guru
William Cosby Junior explains Voice Over IP


William "Bill" Cosby, a man who needs no introduction explains a technology close to his heart, Voice over IP.

I will reach out...
and touch you.

Phone God

Good evening Mr. Cosby. Can I call you Coz?


No, but you can call me Bill. Like the bill I'm gonna send you for all the interviewing.

Phone God

Uhhh. Ok..? I guess, yeah. Well, tell me about voice over IP.


Well, you see..VoIP.... is a revolutionary technology... that has the potential to completely rework the world's phone systems. VoIP providers like the Vonage have already been around for a little while and they're growing steadily, what with the calling and the computers. ..Major carriers like AT&T are already setting up VoIP calling plans in several markets around the United States, and the FCC is looking seriously at the potential ramifications of VoIP service.

Phone God



The interesting thing about VoIP is that there is not just one way to place a call. There are three different "flavors" of VoIP service in common use today:
ATA - The simplest and most common way is through the use of a device called an ATA (analog telephone adaptor). The ATA allows you to connect a standard phone to your computer or your Internet connection for use with VoIP. The ATA is an analog-to-digital converter. It takes the analog signal from your traditional phone and converts it into digital data for transmission over the Internet. Providers like Vonage and AT&T CallVantage are bundling ATAs free with their service. You simply crack the ATA out of the box, plug the cable from your phone that would normally go in the wall socket into the ATA, and you're ready to make VoIP calls. Some ATAs may ship with additional software that is loaded onto the host computer to configure it; but in any case, it is a very straightforward setup. Then there's your IP Phones - These specialized phones look just like normal phones with a handset, cradle and buttons. But instead of having the standard RJ-11 phone connectors, IP phones have an RJ-45 Ethernet connector. IP phones connect directly to your router and have all the hardware and software necessary right onboard to handle the IP call. Soon, Wi-Fi IP phones will be available, allowing subscribing callers to make VoIP calls from any Wi-Fi hot spot. Then you got your Computer-to-computer - This is the easiest way to use VoIP. You don't even have to pay for long-distance calls. There are several companies offering free or very low-cost software that you can use for this type of VoIP. All you need is the software, a microphone, speakers, a sound card and an Internet connection, preferably a fast one like you would get through a cable or DSL modem. Except for your normal monthly ISP fee, there is usually no charge for computer-to-computer calls, no matter the distance.

Phone God

Um..ok. Let's talk about packet-switching versus circuit switching. Tell me about it.


Didn't you know? Data networks do not use circuit switching. Your internet connection would be a lot slower if it maintained a constant connection to the Web page you were viewing at any given time. The data networks, they send and retrieve data as you need it. Instead of routing the data over a dedicated line, the data packets flow through a chaotic network along thousands of possible paths. This is called packet switching. It's like the programming on the NBC. They're always doing the switching and the swapping and doing the things they do to look good, even when they let a real star go.
But like I was saying, the circuit switching keeps the connection open and constant, packet switching opens a brief connection -- just long enough to send a small chunk of data, called a packet, from one system to another. It works like this:

The sending computer chops data into small packets, with an address on each one telling the network devices where to send them.

Inside of each packet is a payload. The payload is a piece of the e-mail, a music file, an illegal copy of the Cosby Mysteries from the warez sites, or whatever type of file is being transmitted inside the packet.

The sending computer sends the packet to a nearby router and forgets about it.Sort of like how the NBC forgot who made they all the money in the 80's, what with my show, which was so good it had a popular spin-off. Anyway, the nearby router send the packet to another router that is closer to the recipient computer. That router sends the packet along to another, even closer router, and so on. They keep passing the buck. It's like the Tom Sawyer with the whitewash, and the Huck Finn, and holding hands with the Becky. hahahahaha.

Now when the receiving computer finally gets the packets (which may have all taken completely different paths to get there, like a bunch of fellahs all thinking they know where the party is), it uses instructions contained within the packets to reassemble the data into its original state.
Packet switching is very efficient. It lets the network route the packets along the least congested and cheapest lines. It also frees up the two computers communicating with each other so that they can accept information from other computers as well.


Phone God

Now what would the advantage here be?


VoIP technology uses the Internet's packet-switching capabilities to provide phone service. VoIP has several advantages over circuit switching. For example, packet switching allows several telephone calls to occupy the amount of space occupied by only one in a circuit-switched network. Using PSTN, that 10-minute phone call we talked about earlier consumed 10 full minutes of transmission time at a cost of 128 Kbps. With VoIP, that same call may have occupied only 3.5 minutes of transmission time at a cost of 64 Kbps, leaving another 64 Kbps free for that 3.5 minutes, plus an additional 128 Kbps for the remaining 6.5 minutes. Based on this simple estimate, another three or four calls could easily fit into the space used by a single call under the conventional system. And this example doesn't even factor in the use of data compression, which further reduces the size of each call.
Let's say that you and your friend both have service through a VoIP provider. You both have your analog phones hooked up to the service-provided ATAs. Let's take another look at that typical telephone call, but this time using VoIP over a packet-switched network:

You pick up the receiver, which sends a signal to the ATA.

The ATA receives the signal and sends a dial tone. This lets you know that you have a connection to the Internet.

You dial the phone number of the party you wish to talk to. The tones are converted by the ATA into digital data and temporarily stored.

The phone number data is sent in the form of a request to your VoIP company's call processor. The call processor checks it to ensure that it is in a valid format and you're not just trying to play the Star Wars theme song on the touch tones.

The call processor determines to whom to map the phone number. In mapping, the phone number is translated to an IP address (more on this later). The soft switch connects the two devices on either end of the call. On the other end, a signal is sent to your friend's ATA, telling it to ask the connected phone to ring.

Once your friend picks up the phone, a session is established between your computer and your friend's computer. This means that each system knows to expect packets of data from the other system. In the middle, the normal Internet infrastructure handles the call as if it were e-mail or a Web page with the naked ladies. Each system must use the same protocol to communicate. The systems implement two channels, one for each direction, as part of the session.

You talk about the sports and and how much you think the Bill Cosby should have bought the NBC when he said he was going to, and during the conversation, your system and your friend's system transmit packets back and forth when there is data to be sent. The ATAs at each end translate these packets as they are received and convert them to the analog audio signal that you hear. You're not hearing the beeping and the buzzing like how a modem makes, because you couldn't understand that, you see. Your ATA also keeps the circuit open between itself and your analog phone while it forwards packets to and from the IP host at the other end.

After you've talked a long time and realize dad is going to be home soon and you need to clean your room, you finish talking and hang up the receiver.

When you hang up, the circuit is closed between your phone and the ATA.

Phone God

Then what?


The ATA sends a signal to the soft switch connecting the call, terminating the session. Probably one of the most compelling advantages of packet switching is that data networks already understand the technology. By migrating to this technology, telephone networks immediately gain the ability to communicate the way computers do.

Phone God

Now how soon do you think it would be before this is fully implimented?


It will still be at least a decade before communications companies can make the full switch over to VoIP. As with all emerging technologies, there are certain hurdles that have to be overcome. You've got your people with the dragging feet, and the buying the new equipment.