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. This requires an analog telephone adapter (ATA) to connect a telephone to the broadband Internet connection. Companies in the U.S., such as Vonage, ATandT, Broadvoice, Time Warner Cable, Comcast, Verizon, Voipex, Packet8, Lingo, 1TouchTone, and SunRocket, use IP to offer unlimited calling to the U.S., and sometimes to Canada or to selected countries in Europe or Asia, for a flat monthly fee. One advantage of this is the ability to make and receive calls as one would at home, anywhere in the world, at no extra cost. As calls go via IP, this does not incur charges as call diversion does via the PSTN, and the called party does not have to pay for the call.
For example, somebody may call someone on a number with a U.S. area code, but one could be in London, and if someone were to call another number with that area code, it would be treated as a local call, regardless of where that person is in the world. However, the broadband phone is likely to complement, rather than replace a PSTN line, as it still needs a power supply, while calling the U.S. emergency services number 911, may not automatically be routed to the nearest local emergency dispatch center, or be of any use for subscribers outside the U.S.
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.
Corporate and Telco Use
Although few office environments and even fewer homes use a pure VoIP infrastructure, telecommunications providers routinely use IP telephony, often over a dedicated IP network, to connect switching stations, converting voice signals to IP packets and back. The result is a data-abstracted digital network which the provider can easily upgrade and use for multiple purposes.
Corporate customer telephone support often use IP telephony exclusively to take advantage of the data abstraction. The benefit of using this technology is the need for only one class of circuit connection and better bandwidth use. Companies can acquire their own gateways to eliminate third-party costs, which is worthwhile in some situations.
VoIP is widely employed by carriers, especially for international telephone calls. It is commonly used to route traffic starting and ending at conventional PSTN telephones.
Many telecommunications companies are looking at the IP Multimedia Subsystem which will merge Internet technologies with the mobile world, using a pure VoIP infrastructure. It will enable them to upgrade their existing systems while embracing Internet technologies such as the Web, email, instant messaging, presence, and video conferencing. It will also allow existing VoIP systems to interface with the conventional PSTN and mobile phones.
Electronic Numbering (Enum) uses standard phone numbers (E.164), but allows connections entirely over the Internet. If the other party uses Enum, the only expense is the Internet connection.
Networks
Aevoe
A company offering a complete serverless hardware VoIP solution without servers or subscription charges for residential or SOHO use. Aevoe products employ SNAP technology so users can keep their regular phone numbers for VoIP calling.
Babble
A UK-based VoIP network.
BroadVoice
A U.S.-based VoIP network that supplies VoIP adapters, or allows customers to use their own SIP devices.
BusinessCom Internet via Satellite
B2B and wholesale SIP/IAX2 VoIP solutions provider.
DOW Networks
VoIP Network Provider, Call Center Solutions, IP PBX, connecting toll-free numbers to VoIP UIFN and ITFS and Hosted Predictive Dialer ASP.
Free IP Call
The Home to Free IP Call, SIP and VoIP Networks Provider.
Free World Dialup (FWD)
A free SIP-based VoIP network.
Gateshare
A U.S.-based VoIP Provider with interconnections with FWD
Gizmo
Gizmo Project uses your internet connection (broadband or dial-up) to make calls to other computers, phones and mobiles. You talk clearly. For as long as you want. For free.
MetroTel
A U.S.-based VoIP Provider with 800 and local numbers
MyCyberphone
A U.S.-based VoIP phone service
MyWebCalls
A UK-based VoIP phone service using SIP and also supporting the Asterisk PBX
Sipgate
A German-based VoIP phone service provider with connections to all UK telephone exchanges, and interworking with all leading VoIP providers.
SIPphone
A free SIP-based VoIP network.
Skype
A proprietary freeware VoIP system which uses a messenger-like client.
Teleo
A VoIP network using a P2P model
TelTel
The largest SIP community
TeleCable Services
A U.S.-based VoIP phone service provider, supplies VoIP adapters or allows customers to use their own SIP devices.
TelSIP
A European-based VoIP network providing the only SIP solution that traverses firewalls and proxies.
ViaTalk
A U.S.-based VoIP phone service
VoIP Solution
A U.S/Canada based VoIP provider, offering USB Bridge (Telephone Adapter) to make mobile and phone calls.
Voipex
A U.S.-based VoIP phone service
Vonage
A U.S.-based VoIP phone service provider
Yahoo! Messenger with Voice
An instant messenging client that now includes VoIP.
Silicon and System-on-Chip
VoIP silicon
VoIP either runs on PC or other multi-purpose platforms or is implemented in general purpose DSP/processors. More recently VoIP core functionality can be implemented better on advanced VoIP system-on-a-chip SoC. The VoIP SoC usually refers to both silicon and software.
VoIP gateway and Terminal system-on-chip advances
The advanced highly integrated silicon and software system-on-a-chip SoC or VoIP SoC for both gateway and terminal. Examples include Entropia and Atlanta products by Centillium Communications Inc.. VoIP SoC for CPE/Terminal may include call processing (e.g. SIP) and other functionality. The focus of gateway VoIP SoC usally is voice processing (codec, EC, etc) and network processing for voice content.
via [ SIPdex - SIMPLE SIP Call SIP Phone ]
