A Little Background on VoIP

VoIP carries telephony signals as digital audio, typically reduced in data rate using speech data compression techniques, and encapsulated in an IP packet stream over aninternet connection. The service has been around for at least 8 years and has reallymatured to the point that it’s become a reliable service, meaning you can count on it as a replacement for POTS for most telephone applications.

VoIP is available to residential customers in two ways. The software only/DIY VoIPimplemented on a PC such as Skype, and the hardware/internet service provider type, such as Vonage. Both types transmit voice packets over the internet and therefore require a broadband connection. The “digital phone service” offered by cable companies is not “true” VoIP. It uses a proprietary encoding placed on an unused cablechannel although many articles on VoIP count them in.

I’m only going to discuss the hardware/service provider implementation because that’s the only option that you can offer to install and set up as a service, assuming you’re responsible for the home network installation. This type of VoIP service is just like using a regular telephone company voice line. The customer is assigned a telephonenumber from the VoIP service provider and can make or receive calls from anywhere. The caller (or receiver of the call) really doesn’t know they’re using a VoIP line.

The advantages of using VoIP, over regular phone service (and cell service), can really make it attractive to your customer.

• Much less expensive
• Many more services such as voice messages delivered over email
• Free long distance in US and may foreign countries
• You can take it with you if you move or travel
• You can choose any area code and even “virtual” numbersConference calling, call forwarding, automatic redial, and caller ID, features thattraditional telephone companies normally charge extra for, are provided in the low flat monthly charge (typically between $15 – $24/month).

There are some disadvantages. Federal law mandates that voice-over-IP services offer Enhanced 911 (or E911), which associates the VoIP phone number with the customers registered physical location so that operators know where to send help. However, 911 service requires not only power but a working internet connection; two conditions thatmay not be available in emergencies. In any case, all VoIP service providers that I’m familiar with offer network-outage forwarding—incoming calls get rerouted to another number (such as your cell phone) automatically if there’s any kind of service interruptionto power, the Internet, or whatever. But you still can’t make outgoing calls from the VoIPconnected phone, which could be dangerous if there’s an emergency. For these reasons, the customer may need at least one regular POTS line.

Also, monitored alarm systems may or may not work with VoIP lines. Your monitoring service will know. It it won’t, you’ll need an alternative connection. A small percentage of customers report problems with fax machines. I’ve never experienced a problem, butfax machines are definitely more sensitive to “voice” quality.

Typical Installation

The figure below illustrates how typical VoIP phone service is implemented. Obviously, VoIP required an existing home network and a broadband internet connection. Anyservice that provides decent download speeds and 90 Kbps upload should work fine.


VoIP requires the use of either a VoIP equipped router or an ATA (Analog Telephone Adaptor) to connect to regular phone line wiring. For reasons that will become obvious, you want a separate ATA. The ATA functions as a gateway, translating audio to and from encoded bytes encapsulated in IP packets and carried (on the LAN) in Ethernet frames.

A typical ATA is shown in the two photos above. This is a Cisco/Linksys PAP2 used by several VoIP service providers. It has an 8-pin modular connector for Ethernetattachment to a router, and two 6-pin analog phone connectors (Line 1 and Line 2). The ATA provides the same analog phone signals as a regular phone line (ringing signal, caller ID codes, etc.), so all regular phone functions work correctly. This allows the customer to attach any type of fixed or portable phone. The ATA also requires power from a plug-in low-voltage power supply.

You have to purchase an ATA that is preconfigured to work with the VoIP service provider you choose. The ATA has the network addresses and VoIP protocol of the service provider in the firmware. You can get them directly from the service provider or from retail and internet stores bundled with a particular VoIP service.

ATA’s are provide free or a very low cost, so if the customer wants to change services, just throw the oldATA away and install a new one. When the ATA is powered on, it connects to the service provider, indicating the phone lines are active. Since the ATA is location independent, it can be used anywhere. This lets the customer can take it if they moveand retain service and phone number.

The best place to install the ATA is in the structured cabling enclosure since this is typically where CAT5 for phone outlets are terminated. This may our may not be wherethe router and/or switch is placed. If it is, great. If not, you’ll need a cable from thenetwork switch to the structured cable “can” for the ATA. The figure below illustrates atypical installation. This shows a POTS line and the two analog lines from the ATAterminating in a phone line punch-down module. From there, cables can be connected to any telephone jacks you need by punching them down to the module.

This is a very nice configuration for a home office. It provides either two VoIP phone lines or a phone and fax line as well as connection to a standard telephone line for thefamily.

Configuring the ATA

Once installed, the ATA will require configuration like any other attached network device. But unlike most network device, the ATA uses an attached telephone to perform the configuration via the touch-tone keypad and voice responses (like configuring a voicemail service). You’ll need to assign it a static IP address, subnet mask, turn off DHCP, etc., like any other networked device. There may be additional phone related functionsto configure depending on the capability of the ATA.

Network Requirements

Years ago, installing an ATA required manually opening various ports on the router. Today, most ATA’s I know of have firmware that gets around the problem. They openthe necessary router ports by initiating outgoing packets through the router that are inturn used by incoming VoIP packets. VoIP service servers will use the same ports.

VoIP requires very little bandwidth, at least 80-90 Kbps upload speed for good voice quality, but it’s fairly sensitive to network “jitter” (packet latency). This can result from network congestion (which you have no control over), or other users on the same LANsharing the upload bandwidth (which you have some control over). In this case, usinga router with some sort of QoS configuration can make a difference. This means assigning a high QoS priority to outgoing packets from the IP address of the ATA. Most commercial routers (which you should be using anyway) have this capability. Isolatingthe ATA on it’s own VLAN can also help (see our Advanced Home Network course for details).

VoIP Providers

There are dozens of VoIP service providers to choose from. Just a few of the better known companies include Vonage, Voip.com, Packet8, Road Runner, and Lingo. Vonage is the “grandaddy” of VoIP providers. It’s been around since January of 2001, has over 2.6 million subscribers, and is publicly traded. I’ve used Vonage since 2003 and have had very good service.

In fact, it is so good I don’t realize I’m using VoIP. I can access all my incoming and outgoing call histories via the Vonage web site, check my bill, add services, etc. Voice messages are sent to me via email as an attached .wav audio file. However, Vonage has a poor reputation for customer service, especially if you want to cancel it, so it’s probably worth doing a little shopping around and checking reviews of providers.

There are some other caveats: VoIP providers are NOT phone companies. They’resmall companies with correspondingly small support staff. Troubleshooting help may be even more difficult than the regular guys. However, some VoIP providers have received rave reviews on customer service. They are vulnerable to Internet congestion and otherproblems they have no control over and can’t improve.

Like many service oriented “products” you can offer, VoIP is best demonstrated in a showroom so you can show the client how easy it is, how well it works, and how simpleit is to add to your proposal.

* You might be able to make money on bundling the service with your install. Vonage has “professional” installation service advertised on their web site, so they have obviously contracted with someone to do it in many parts of the country. It may as well be you!

If you have any questions about anything in this TIP or VoIP story to relate, drop me an
e-mail at grayson@trainingdept.com I will actually answer it!

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