Communication technology » Data Packet

VoIP Tutorial

admin — Fri, 22 Jan 2010 07:25:38 +0000

VoIP or voice over protocol is one of the latest innovations in communications technology. The main difference it has with the old telephony system is that it uses data packets while the old telephony system uses switch boards.

In case you are not familiar with switchboards, imagine your call being routed to an operator before it reaches the person you are calling. That illustrates how a switchboard works. VoIP uses data packets that are sent and received via the internet. Hence, the basic equipment you will need to enable VoIP is a modem because this is the main device that allows you to get an internet access.

VoIP products come as trunk or hosted. If you are still wishing to use your old telephone device while utilizing VoIP at the same time, you will need to purchase a gateway from VoIP vendors. The gateway comes in a data packet that looks like a box. You would have to connect this to your conventional telephone or fax machine to enable VoIP. However, if you have an IP enabled system, there is no need to purchase the gateway.

There are four ways by which you can make the calls using the VoIP. These include internet-internet, phone-internet, internet-phone, phone-phone. If you are making a call towards a phone, it can be a regular, non-VoIP phone. Otherwise, the recipient of your call also needs to have a VoIP-enabled device. If you are making a call through a computer, you need to have a head set and a VoIP software program. If you are making an internet-internet call, the computer you are calling to must also have the same software as you have. Examples of this software are Skype, that of Yahoo, MSN, etc.

By: Elija James

Understanding The Magic of Bluetooth Technology

admin — Wed, 06 Jan 2010 02:56:30 +0000

Bluetooth technology is a low-power, low-cost wireless technology for short-range radio communication between various fixed and/or portable electronic devices such as mobile phones, laptops, PDAs, cars, stereo headsets, MP3s, digital cameras, PCs and computer peripherals. Bluetooth also refers to the standard communication protocol (IEEE 802.15.1) specifically designed for this kind of short-range wireless communication.

The core of Bluetooth technology lies in a low-cost 9 mm x 9 mm microchip that functions as a short-range radio link when inserted into an electronic device, making the device Bluetooth-enabled. Wireless communication between various bluetooth-enabled devices takes place via these radio links, instead of via cables as used in normal networking. Since Bluetooth technology uses radio signals, which are omni-directional and can be transmitted through walls and other obstacles, Bluetooth-enabled devices don’t need to be in line of sight or be pointing at each other.

Bluetooth radio modules operate in the open, unlicensed ISM (industrial–scientific–medical) spread-spectrum 2.4 GHz frequency band, divided into 79 channels separated by 1 MHz each. To avoid interference from other signals, the Bluetooth signal hops to a new channel every time it transmits or receives a data packet, making Bluetooth connection robust and secure. The communication range of Bluetooth technology varies from 1 m to 100 m, depending upon the maximum power permitted (1 mW to 100 mW). Because of this channel hopping, there should not be a consistent problem with other devices using the 2.4 Ghz frequency band, such as old cordless phones.

Each Bluetooth-enabled device can simultaneously communicate with up to seven other devices within a single personal area network, called a piconet. Each device can simultaneously belong to several piconets. Each device negotiates with each other via a defined device name so that each device can keep track of who it is communicating with. The device name to use when you are setting up your Bluetooth device is typically cleared stated in the accompanying device documentation.

Bluetooth technology offers built-in security with 128-bit encryption and PIN code authentication. When Bluetooth products identify themselves, they use the PIN code the first time they connect, thereafter staying securely connected.

Practical Applications of Bluetooth Networking

Some of the popular applications of Bluetooth technology are in wireless networking between a mobile phone and a laptop/desktop, between a mobile phone and a hands-free headset, between PCs in a restricted space and between the input and output devices of a PC (e.g., mouse, keyboard, printer). Bluetooth technology can also be used to transfer files, images and MP3 files between mobile phones or between MP3 players/digital cameras and computers.

Limitations of Bluetooth Technology

Short communication range (up to 100 m) is the greatest limitation of Bluetooth technology. Also, the data transfer rates are much lower compared to other wireless communication technologies. Susceptibility to interference from other devices operating in the 2.4 MHz band, notwithstanding adaptive frequency hopping, is another limitation. The Bluetooth technology is still not fully developed, so there is plenty of room for improvement.

Bluetooth-Enabled Devices

The Bluetooth wireless technology specification is available free-of-charge to Bluetooth member companies around the world. Many companies are interested in making their devices Bluetooth-enabled in order to avoid the clutter of wires with seamless connections and offer simultaneous transmission of data and voice as in hands-free talking.

Bluetooth technology is commercially available in a wide range of applications such as mobile phones, automobiles, medical devices, play stations and many more.

By: Jon Arnold

Internet Protocol Telephony

admin — Sun, 27 Dec 2009 00:49:20 +0000

Many people have family and friends based in foreign countries and they often use the long distance phone service of traditional operators to communicate with them. Many times, these long distance calls are very expensive and unaffordable to low budget users. However, with the introduction of a new kind of communication technology called Internet protocol (IP) telephony, making long distance calls has become affordable even for low budget users.

IP telephony is the use of Internet protocols for the purpose of voice phone calls that can be made over the Internet or other packet networks such as LAN and WAN. The equipments required for this purpose are a standard telephone and a good PC with a properly installed sound card.

Protocol is a fundamental set of programs for network communication and is the most important specification that needs to be considered while searching for IP telephony devices. Protocols specify the software features that need to be used for data communication, which includes the information and structure of the data packet. The popular network protocols used for the purpose of IP telephony are IPX, TCP/IP, AppleTalk, ATM, ControlNet, DeviceNet, Ethernet, 10 Base T Ethernet, 10 Base 2 Ethernet, and 10/100 Ethernet, to name a few.

After protocol, the port performance specifications and features are the next types of specifications that need to be considered for IP telephony. A wide variety of choices are available for users to choose the right kind of port for their system such as AUI, BNC, GBIC, MIC, RJ-45, SC, ST, ISDN BRI S/T and USB and many more. The number of ports used is very important for proper and efficient working of IP telephony.

Performance specifications such as the data rate, operating temperature and number of users are the other specifications needed for the proper use of the ports. It is essential for customers to seek appropriate guidance and help from qualified professional technicians in order to experience stress free installation of IP telephony.

By: Eddie Tobey

How VoIP Works — Busting Out of Long Distance Rates

admin — Sun, 29 Nov 2009 03:29:19 +0000

VoIP is the newest advancement in audio communications technology, and has a
variety of different applications that make it useful. VoIP stands for Voice
over Internet Protocol, and how VoIP works is actually quite revolutionary
because it streamlines the process of sending analog audio signals by converting
them to a much easier to send digital form for transmission.

To understand how VoIP works, you’ll need to understand the basic concept
behind regular analog audio communication as well, since this is the precursor
for VoIP. Analog phone calls are actually made via fiber optic networks by
digitizing your voice communications for sending the signal across thousands of
miles, but once it gets to the final destination (a home or office phone, for
instance), the signal is once again converted to analog.

During these calls, the switches remain open even while there is dead air and
no conversation is taking place; the circuit is also open in both directions
even when only one party is talking and the other is listening. This isn’t
terribly efficient, and slows down the communication of information
considerably.

Packet switching streamlines VoIP

VoIP works on a different premise — rather than circuit switching, data
packet switching sends and receives information only when you need it instead of
in a constant stream. It also sends the information packets along whatever open
channels are available rather than a dedicated line, which is much more
efficient. The information is simply reassembled at the source.

The payload of each packet has a destination coded into it determining the
ultimate destination. When the computer at the other end receives all of these
packets, it will reassemble the information into useable form. This form of
sending audio data is extremely efficient because it always takes the cheapest
route that is also the least congested.

The compression of information and use of multiple routes in order to send
that information over the most efficient route makes sending audio over packet
switching quicker, much less expensive and more efficient. The number of calls
that can be sent is orders of magnitude higher than it was with the more
traditional analog circuit switching systems.

For companies, the savings in long distance charges can be in the hundreds or
even thousands of dollars per year. If companies also make extensive conference
calls, VoIP makes even more sense when combined with conferencing options such
as document sharing in systems offered by companies like Voxwire and iVocalize.

Different types of VoIP calling are available

The most commonly used VoIP system is from one computer to another. To set up this type of service, you will need to have a sound card installed in both computers along with microphones and Internet connections. For practical purposes, you’ll want a broadband connection or DSL — a dial-up modem will be so slow the sound quality just won’t be that good. Aside from that, all you need is a software package that can set you up with everything you need to use VoIP to make phone calls to whomever is also set up with the same system. You can also invest in IP phones if you want something that looks just like your standard analog telephones but with VoIP connectability. These simply replace the old-style RJ-11 connectors with Ethernet connectors (RJ-45). Hardware such as routers and the needed software are built right in. Analog telephone adaptors (ATA) enable you to connect a standard telephone to your computer Internet connection in order to take advantage of VoIP options. ATA converts analog signals to digital so that it can be transmitted properly via the Internet. The newest option on the market is the Wi-Fi phone, which uses short-distance Internet transmission of VoIP to replace cell phones calls. Wi-Fi broadcasts over the radio spectrum to cover short range areas for users in certain areas, and these “hot spots” have popped up across the U.S.

The upshot of VoIP is that standard long-distance charges may soon become a
thing of the past. As more and more consumers turn on to VoIP and broadband
connections make it easy and inexpensive (as well as practical) to make phone
calls over the Internet, fewer individuals will be willing to pay high rates to
make a telephone call they can make for free or next to nothing via their
computer.

VoIP saves you money on long distance

There’s no by-the-minute charges with VoIP, no set-up fees, and no “time of
day” or overages. That’s the great thing about VoIP plans. You just pay a
monthly fee and get to make all the calls you want over your computer for one
monthly fee. It’s so simple and elegant, and it’s the solution that everyone’s
been wanting and waiting for far too long.

You don’t have to wait for a certain time of day of day of the week to make
telephone calls with VoIP. There’s also the advantage of being able to use your
VoIP connection from anywhere — remember, you’re not tied to a phone jack to
use your number, but an Internet connection, so you can call from anywhere with
many calling plans.

Some of the companies that offer excellent VoIP plans with unlimited calling
are listed below with their most popular options:

Vonage currently offers a $24.95 per month unlimited VoIP package to anywhere in the U.S. or Canada. It includes voicemail, call forwarding, three way calling, call waiting and caller ID. Packet 8 can provide unlimited VoIP for $19.95 a month in the U.S. and Canada with a variety of features like call waiting and three-way calling, and can also give you video phone service for about $29.95 per month. AT&T’s CallVantage provides the usual U.S. and Canada broadband calling with voicemail, call waiting, etc. along with email, a call log and a ‘do not disturb’ option, all for $29.99 a month. You also get to keep your phone number for life, no matter where you go — a great feature for some who move around a lot.

VoIP in web conferencing packages

VoIP is used in almost all web conferencing services as an alternative to
standard conference calls, and looking into these packages will give you an idea
of some ways to combine VoIP with extras such as white boards, document sharing
and video. For less expensive options, many companies can provide strictly audio
VoIP conference calls combined with text messaging and document sharing without
video.

Some companies that offer VoIP in web conferencing packages separate from
video conferencing are:

Voxwire offers voice communication with features like auto-queue, mute options, individual speaker adjustments and moderator controls along with a “follow me” browser system so that all participants can view a shared desktop. Two persons can use VoIP for $9.95 a month, or up to ten in a conference environment for $29.95 per month. VoiceCafé provides similar services with a wide range of options that vary from packages with VoIP capability for five people at a time on a conference call to up to 500 in one conference call, all for a flat monthly fee. The prices vary depending upon what package you choose, and there are several. iVocalize offers VoIP along with Internet conferencing options like PowerPoint presentation capabilities and presentation recording for future playback. They also provide optional Unicode translation in thirteen languages. The most basic VoIP package begins at $10.00 a month with a prices going up incrementally depending upon your needs and how many will be involved in your conference calls.

It is obvious that conference calling as well as standard long distance
calling will be changing greatly in the near future as VoIP changes the
landscape of telephone service. “Land lines” for long distance calling will
eventually become obsolete as broadband becomes more common and makes VoIP just
as commonplace as any other type of telephone call.

And with the greater portability of soft phone options built into laptops and
the use of ATA phone adapters, the use of VoIP in the average home will arrive
sooner rather than later.

This article on the “How VoIP Works” reprinted with
permission.