From: www.quickstartvoip.com

Free Internet phone service lets you to make free long distance calls over the Internet in three different flavors. The first enables you to make calls from one phone to another as long as both are connected to broadband lines. The second allows you to make calls from one computer to another and the third makes calls possible from a computer to a traditional phone.

But, there are limitations to free services. Let’s take a look.

Phone-to-phone service providers require that you purchase their telephone adaptor (or ATA). As long as you are calling other people who have purchased the same equipment, the call is free. PhoneGnome is one such service. The PhoneGnome adaptor costs about $119. You literally plug it in to your broadband connection and to your regular phone, it configures itself, and you are good to go. You can start calling other PhoneGnome users anywhere for free. You don’t have to switch phone numbers or change telephone companies. Vonage, Packet8, AT&T CallVantage, and others you may have heard of follow the same model.

PC-to-PC service providers allow users to make free calls from one PC to another. Both parties need a PC with an Internet connection and some software easily downloaded from the Net. However, for a call to ring through, both parties have to be online at the same time and have the same, or at least compatible, software. By adding voicemail to a PC-to-PC service though, callers can leave messages even when you’re not online. Unfortunately, voicemail may or may not be free.  Skype, Gizmo Project, and FWD are three typical PC-to-PC services.

PC-to-phone services let you to call a regular phone numbers for free. However, you may be restricted to the locations that you can call or the length of the call. VoipBuster, for example, provides free calls from your PC to landline phones in about 30 countries. The restrictions are a little bit complex, but free is free…Lucky for us, the bigger software-based phone companies are trying hard to entice users so there’s also a current wave of promotions trumpeting free calls to landline phones. Skype for example offers free calls to any phone within North America until the end of the year. Gizmo offers free calls to phones in 60 countries as long as both parties maintain an active Gizmo Project account.

In all of these cases, free Internet telephone services make money by selling credits for calling minutes to landline phones or mobiles, long distance destinations, or phone numbers not on the same VOIP service. Rates are low, however, and you can expect to save significantly over traditional long distance companies. For regular phone users to call you on your free Internet phone account, you must “buy” or subscribe to a conventional phone number. Most services allow you to buy a phone number in different locations, so if your family is in the UK and wants to phone you regularly, you can buy a local UK number that they can call for free or inexpensively.

Reprinted with permission from: www.quickstartvoip.com

When shopping around for a VOIP phone, no doubt you’ll come across buzzwords like: softphone, SIP phone, IP phone, and Internet phone.

Do all these terms mean the same thing, or is there a difference? Let’s take a look.

VOIP phone or Broadband phone: A handset used to make VOIP calls. A VOIP phone has an Ethernet port (RJ-45) instead of regular phone jack (RJ-12), and they connect directly to a broadband Internet modem. A VOIP phone does not require a computer or softphone application to make or receive calls. A high speed Internet connection and subscription to VOIP phone service is all that is required. A SIP phone is a type of VOIP phone.

SIP Phone: A VOIP handset that complies with the SIP standard for voice over IP. SIP is the latest open standard, succeeding H323 standards. Bottom line, SIP compatibility is good. Phones that compete with SIP use proprietary signaling protocols for voice over IP. SIP softphones are VOIP software applications that comply with SIP standards.

IP phone: An umbrella term but used to mean any phone that can be used on an IP network (like the Internet). An IP phone may comply with either proprietary or open standards for voice signaling. An IP phone doesn’t have a RJ-12 connector like regular phones.

Internet phone: This term is used pretty loosely and depending on the context can mean the same as IP phone.

Softphone: A software application that lets you make calls over the Internet using the mouse or keyboard to dial phone numbers. To use a softphone, your computer must have an sound card, plus a speakers or headset, and a microphone. A USB phone can take the place of headset and microphone. Softphones are often free to download. Free VOIP software such as Skype and Free World Dialup are two popular choices.

USB phone: A handset that connects to the USB port on your computer. It is used for convenience when dialing from your computer, but it requires that a softphone application be installed first. Instead of using the softphone with a headset or microphone, the USB phone looks and acts like a regular phone and keypad. USB phones require driver software to be installed on the computer.

WiFi phone or WLAN phone: A handset used for making wireless VOIP calls. It has a  built-in WiFi transceiver unit instead of an Ethernet port. When you talk over WiFi, the phone connects wirelessly to a WiFi base station and from there to the Internet and a remote VoIP server. A computer or softphone is not required to make and receive VoIP phone calls. All that is required is access to a WiFi base station. Many cell phone companies are developing handsets with WiFi capability. This means you can make calls on the regular cell phone network and make VOIP calls on a local WiFi network (called a WiFi hotspot).

Skype phone: A handset that is much like a USB phone, except that the softphone application used to make the calls is Skype. A Skype phone can only make calls using the proprietary Skype phone software running on your computer. Linksys recently announced the release of its CIT200 wireless Skype handset which makes using Skype convenient from anywhere in the home.

Web phone: A marketing term that has been used to mean many things, both softphone and IP phone-related.

Net phone: Same as IP phone

Computer phone: See softphone, PC phone or USB phone.

PC phone: See computer phone, softphone or USB phone.

Reprinted with permission from: www.quickstartvoip.com 

You may have heard this before: Voice Over IP (VOIP) needs a certain amount of bandwidth to be usable. In other words, VOIP needs bandwidth so that voice conversations are intelligible by both parties. Your broadband Internet connection (provided through a cable or DSL service) provides that bandwidth.

Basically, bandwidth is the amount of digital data that can be transmitted in a certain time period. Internet connections are usually measured in KiloBits Per Second (kbps). Your connection may be rated at 512/128 kbps. This means that the upload stream (leaving your computer) has a maximum bandwidth of 128 kbps and download stream (coming to your computer) has a maximum bandwidth of 512 kbps. Find out the speed of your broadband connection…

For example, a web page that is 3000 bytes can theoretically viewed in 0.05 seconds – almost instantaneously – at a download speed of 512 kbps. However, in the real world web pages don’t usually load that fast.  That’s because data is held up, or delayed by various factors. Latency is the delay caused by the physical limitations of each piece of hardware the data is passed through. Delays are also caused by pathway congestion, error checking, transmission negotiations and extra data sent with the web page to identify its type, origin and destination.

What this means for VOIP is that enough bandwidth must be supplied to allow for the transmission of the actual voice data in real time as well as extra bandwidth for the overhead required for any data transmission.

So how much bandwidth does voice data use up? Well that depends on the codec (enCOder/DECoder) used to compress the data. Anywhere from 16 to 64 kbps is normal. Add onto that the extra overhead of about 10 to 24 kbps. In total, VOIP uses 26 to 88 kbps. As a general rule, assume that you will need at least 88 kbps to use VOIP reliably. Note that VOIP service providers will provide you with their broadband requirements.

You will need an Internet connection that can handle at least 128 kbps on the upload side. Extra bandwidth will allow others in the household to surf the net or download files while you are talking on the phone. If you wish to use conference calls even more bandwidth will be required.

While there is no set rule for the amount of bandwidth that a household will need, count on 128 kbps as a minimum.  If you have several computers and other devices connected to the Internet, consider going up to the maximum available.

Note that these speed are for uploads – the download speeds are usually quite a bit faster and present no problem for VOIP.

Reprinted with permission from: www.quickstartvoip.com

In order to use VoIP, both parties need a broadband connection. This is a high-speed Internet, or broadband connection usually provided by a cable or DSL modem. Broadband modems are usually used to connect computers to the Internet, but in the case of VoIP, computers are not necessary.

The simplest form of VoIP is a computer-to-computer voice connection. All that is required for this type of connection is a computer, a headset consisting of earphones and microphone, and VoIP software. Most software packages are free and allow you to connect to any computer running the same software. There is no charge for this type of connection and calls can be made to anywhere in the world.

VoIP software can also be used to connect to land-line phones — that is, phones which are not connected directly to the Internet. This type of call is usually not free but the cost is quite a bit lower than what your telephone company charges. Some VoIP services also allow you to make calls to cellular phones.

The only time that both parties need a particular VoIP software package is when they are making computer-to-computer calls. Parties receiving land-line or cellular calls do not need any extra equipment or software.

VoIP Transmissions

VoIP is based on digital data transmission. The first step in any VoIP call is to convert the analog signal of the human voice into digital data. This is done within an Analog-to-Digital Converter (ADC) that divides an analog signal into discrete steps which are represented by numbers. The next step is to compress the audio data using a codec (enCOder/DECoder) which significantly reduces the amount of digital data while maintaining audio quality.

The compressed digital data can now be sent over the Internet. The data stream must be divided into packets which, besides containing the audio data, also have information concerning their destination and their place in the data stream.

All data that is sent over the Internet is encapsulated in ‘layers’ which aid in its proper delivery. For example, web pages may use the Internet Protocol (IP) network layer to specify destination and origin addresses, the Transmission Control Protocol (TCP) transport layer to create a connection between two computers and the Hyper Text Transfer Protocol (HTTP) as an application layer to allow the Web browser to display the web page correctly.

Most VoIP uses a transport layer called User Datagram Protocol (UDP) which is faster than TCP. A commonly used application layer is Real-time Transmission Protocol (RTP) — originally developed for delivering audio and video over the Internet. RTP provides information about the sequence of the data packets so they can be reconstructed in the correct order at their destination.

RTP also has the ability to drop packets if they do not arrive within a certain amount of time. This is necessary for telephone conversations because if the telephone software waited for every packet of information to arrive before reassembling it there would be unacceptable delays in the audio stream.

Even though some of the packets are dropped, there is usually still enough information to make the conversation legible. The number of packets that will be dropped depends on the speed of your Internet connection in the distance between the two parties.

Once the voice data has arrived at its destination, it is reassembled in the correct order and converted back from digital to analog.

Before you sign on to a VOIP service or plan, make sure that your broadband connection is up to snuff.

Voice Over IP (VOIP) needs a certain amount of bandwidth to be usable. Bandwidth is the amount of digital data that can be transmitted in a certain time period.

In general, an upload speed of 88 Kbps is recommended, although each VOIP service provider will have their own requirements.

You can test your current broadband Internet connection (provided through a cable or DSL service) using the free web tools. Here’s a couple to try:

• Vonage broadband speed test — automatically tests your upload and download speeds.
• TestYourVOIP.com — tests your broadband connection in a real VOIP call (requires Java enabled browser)