Mass-market telephony
A major development starting in
2004 has been the introduction of mass-market VoIP services over
broadband Internet access services, in which subscribers make
and receive calls as they would over the PSTN. Full phone service VoIP phone companies provide inbound and outbound calling with
Direct Inbound Dialing. Many offer unlimited calling to the U.S.,
and some to Canada or selected countries in Europe or Asia as
well, for a flat monthly fee.
These services take a wide variety
of forms which can be more or less similar to traditional POTS.
At one extreme, an analog telephone adapter (ATA) may be connected
to the broadband Internet connection and an existing telephone
jack in order to provide service nearly indistinguishable from
POTS on all the other jacks in the residence. This type of service,
which is fixed to one location, is generally offered by broadband
Internet providers such as cable companies and telephone companies
as a cheaper flat-rate traditional phone service. Often the phrase
"VoIP" is not used in selling these services, but instead the
industry has marketed the phrases "Internet Phone", "Digital Phone"
or "Softphone" which is aimed at typical phone users who are not
necessarily tech-savvy. Typically, the provider touts the advantage
of being able to keep one's existing phone number.
At the other extreme are services
like Gizmo Project and Skype which rely on a software client on
the computer in order to place a call over the network, where
one user ID can be used on many different computers or in different
locations on a laptop. In the middle lie services which also provide
a telephone adapter for connecting to the broadband connection
similar to the services offered by broadband providers (and in
some cases also allow direct connections of SIP phones) but which
are aimed at a more tech-savvy user and allow portability from
location to location. One advantage of these two types of services
is the ability to make and receive calls as one would at home,
anywhere in the world, at no extra cost. No additional charges
are incurred, as call diversion via the PSTN would, and the called
party does not have to pay for the call. For example, if a subscriber
with a home phone number in the U.S. or Canada calls someone else
within his local calling area, it will be treated as a local call
regardless of where that person is in the world. Often the user
may elect to use someone else's area code as his own to minimize
phone costs to a frequently called long-distance number.
For some users, the broadband
phone complements, rather than replaces, a PSTN line, due to a
number of inconveniences compared to traditional services. VoIP requires a broadband Internet connection and, if a telephone adapter
is used, a power adapter is usually needed. In the case of a power
failure, VoIP services will generally not function. Additionally,
a call to the U.S. emergency services number 9-1-1 may not automatically
be routed to the nearest local emergency dispatch center, and
would be of no use for subscribers outside the U.S. This is potentially
true for users who select a number with an area code outside their
area. Some VoIP providers offer users the ability to register
their address so that 9-1-1 services work as expected.
Another challenge for these services
is the proper handling of outgoing calls from fax machines, TiVo/ReplayTV
boxes, satellite television receivers, alarm systems, conventional
modems or FAXmodems, and other similar devices that depend on
access to a voice-grade telephone line for some or all of their
functionality. At present, these types of calls sometimes go through
without any problems, but in other cases they will not go through
at all. And in some cases, this equipment can be made to work
over a VoIP connection if the sending speed can be changed to
a lower bits per second rate. If VoIP and cellular substitution
becomes very popular, some ancillary equipment makers may be forced
to redesign equipment, because it would no longer be possible
to assume a conventional voice-grade telephone line would be available
in almost all homes in North America and Western-Europe. The TestYourVoIP website offers a free service to test the quality of or diagnose
an Internet connection by placing simulated VoIP calls from any
Java-enabled Web browser, or from any phone or VoIP device capable
of calling the PSTN network.