Internet VoIP Phone Services
Internet VoIP phone
services include any service that can provide phone services over the
Internet. These services are popular for providing low-cost additional
phone lines to homes. Typically, the service has components like those
shown in Figure 1.
In
the home, you would have a terminal adapter (also referred to as an
Analog Terminal Adapter, or ATA), which would enable the phone handsets
in your home to work with digital VoIP. High-speed broadband Internet
access provides the connection to your phone provider.
At the provider, a softswitch
(a big computer) typically acts as the central office to route calls to
and from phones. There is usually a subscriber database and a
voice-mail server, as well as a gateway to the public switched telephone
network (PSTN) for “off-Net” calls (that is, calls that originate or
terminate on a different network than the broadband phone service
provider’s).
With this type of
service, you are assigned a phone number, and your dialing is nearly
identical to that of the PSTN. Features provided are also similar to the
PSTN . Costs range from $10 to $50
per month, depending on the features included and whether unlimited
local and long-distance calls are included.
Table 1
presents some examples of this type of phone service.
Cable VoIP Digital Phone Services
Cable VoIP phone
services are similar to Internet VoIP services (actually they are kind
of a subset). The primary difference is that your cable provider, which
typically provides you with high-speed broadband Internet access, also
provides you with a VoIP-based digital phone service. These services are
increasingly popular as a replacement for your primary PSTN line.
Typically the service has components like those shown in Figure 2.
In
this case, the broadband cable modem usually serves a dual role, also
acting as the terminal adapter that converts the handsets in your home
to digital VoIP. High-speed broadband Internet access provides the
connection to your phone provider.
Just as with an
Internet VoIP provider, a softswitch would typically act as the central
office to route calls to and from phones. There is usually a subscriber
database and a voice-mail server, as well as a gateway to the PSTN for
“off-Net” calls (that is, calls that originate or terminate on a
different network than the cable VoIP service provider’s).
With this type of service,
you are also assigned a phone number, and your dialing is nearly
identical to that of the PSTN.
What differentiates a
cable VoIP service is that your high-speed broadband cable provider is
also the VoIP provider. In this case, calls are not typically
transported across the public Internet, but instead are routed directly
from the broadband cable network to the VoIP switch. Costs range from
$40 to $60, depending on the features included and whether unlimited
local and long-distance calls are included.
It’s
worth mentioning that even if you get Internet access from a cable
provider that offers VoIP service, you can choose VoIP from a different
provider. |
Most cable providers offer a form of cable VoIP service, including those shown in Table 2. Cable providers are specific to your geographic area; this table lists some of the largest in the United States.
VoIP Chat Services
VoIP chat services are a
bit different from Internet VoIP and cable VoIP services. While those
services operate similarly to PSTN telephone services, including being
assigned a normal phone number, VoIP chat services work much more like instant messaging (IM) programs, and are often referred to as PC-to-PC calling.
These services are rapidly growing as a low-cost method for
international calling and are popular with teenagers for general
unlimited talking to each other. Typically, the service has components
like those shown in Figure 3.
In this case, you have
no distinct terminal adapters in your home. The terminal adapter
function is provided by a desktop or laptop computer. Another difference
is that your computer (or game system, if you use Xbox Live) also
usually serves as the handset, and it’s generally not a service to which
you would connect your traditional PSTN handsets. High-speed broadband
Internet access provides the connection to your VoIP chat provider.
Note
A
wireless handset is available from Linksys (CIT200 Cordless Internet
Telephony Kit) that works with one of your home computers as the base.
This allows you to access a VoIP chat service (such as Skype) using a
cordless phone, instead of using a headset connected to the computer. |
With this type of service, you are usually not
assigned a phone number. Your typically method of calling each other is
to look up the person in the contact list on your computer and click
his or her name, similar to IM. With some services, you can call PSTN
phone numbers as well (usually at a premium charge). The features
provided are typically similar to IM features, not the fancier PSTN
features found in Internet VoIP or cable VoIP services.
There are a growing number of providers that offer VoIP chat services. Table 3 lists the most common ones.
