Pros: Free to use, easy to set up,
gets you started on VoIP easily
Cons: Both parties need to be
running the same 3rd party VoIP software, computer required
Computer to phone - $$
Computer to phone is the next step up the ladder
and a point at which VoIP telephony service providers start making money.
Computer to phone connection is popular among those who make a lot of
international calls. The difference to a normal international
landline telephone call is that the per minute charge is usually in
pennies rather than tens of pennies or more.
From the viewpoint of the person making the call
this service works in much the same way as Computer to Computer in that
you make your call via a 3rd party piece of VoIP software using a headset
or USB phone. The difference though is that the person you're calling can
have a regular landline phone and doesn't need to be connected to the
internet or be running a 3rd party piece of VoIP software.
This is achieved by your VoIP telephony service
provider connecting your call to the regular landline phone exchange and
routing your call to the desired landline number. It's this bit you are
Pros: Cheap calls to any landline
phone in the world, easy to set up
Cons: You still need your computer
and VoIP software to use this service, generally can't make emergency
SIP to SIP
SIP is the Voice over IP (VoIP) standard
communication protocol. SIP enables two or more people to make phone calls
to each other using the Internet to carry the call.
SIP to SIP calls can be made using SIP hardware or SIP software, either
way you need an internet connection.
If using SIP software then it pretty much becomes
Computer to Computer connections and the same rules apply, this can be
extended to use Computer to Phone connections but will cost as shown
If using SIP hardware phones then all calls to
other SIP hardware phone users are free. This is especially useful for
global businesses who can set up each office with SIP phones.
Communication anywhere in the world then becomes free with the familiarity
of using a phone.
The use of your traditional phone can also be
used with the use of a SIP adapter, negating the need to replace handsets.
Pros: SIP is the VoIP communication
standard so is likely to be well supported in years to come. Same benefits
as Computer to Computer VoIP, can use phone handsets
Cons: SIP phone software / hardware
required by both parties if calls to be made free, generally can't make
emergency services calls.
Phone to phone
The ultimate VoIP service if VoIP is going to
compete with traditional landline calls.
Telephone calls are made using the services of a
specialist VoIP service provider. Behaves like a normal phone service.