VoIP

A technology that uses Internet Protocol (IP) instead of voice recognition as the conduit for a voice conversation by telephone. The technology transmits ordinary telephone calls over the Internet using packet-linked routes. It was developed because in 1999, the volume of data traffic surged past the volume of voice traffic on worldwide networks. Early visionaries saw that the packet networks of the Internet could carry voice as well as data, and now AT&T uses Internet protocols to route some of its long-distance calls. This technology permits inexpensive overseas calls via the Net.

Historical perspective: As seen in Conde Nast Traveler, Alex Pasquariello reports on the five most popular VoIP (Voice over Internet Protocol) powered services in 2011. Which one is for you?

1) For old-school travelers who still use hotel-room phones, the best way to call is using VoIP calling cards, including Pingo.com, Enjoyprepaid.com, and Comfi.com. What do you need? A landline and a card or online account loaded with pre-paid credit.

The fundamentals of the classic calling card remain: Pick up a landline, dial a toll-free local access number, enter a PIN and an account number, and reach out and touch someone. What's new is that your entire call—whether to a landline or a mobile number—is routed over the Web, which translates into super-low rates. Cost: Varies by destinations but ranges from 5 cents to 50 cents per minute. Drawbacks: VoIP calling card services are available from a limited number of countries. Connection fees can offset the great rates.

2) For tech-savvy travelers who want voice and video chat, the best way to call is Skype. What do you need? A laptop, Android phone, iPhone, or iPod Touch. 

A pioneer in VoIP applications, Skype remains the go-to service for travelers who are wired and who have consistent Wi-Fi access. Skype's mobile app, designed to work with the new generation of camera-enabled iPhone and Android devices, means you can leave the laptop at home. Voice and video chat to other Skype users is picture- and pitch-perfect. Cost: Free when calling other Skype users; rates from 2.3 cents per minute for calls to landlines and mobiles in 42 countries when you pay as you go, and even lower with a $14 monthly subscription. Drawbacks: Forgetting to turn off data service when using Skype mobile abroad can quickly lead to sky-high international data charges.

3) For globe-trotting Apple fanboys and girls, the best way to call is Apple FaceTime. What do you need: An iPhone, iPod Touch, or MacBook. 

A super-simple Wi-Fi video-chat app available on the latest iPhone, iPod Touch, and MacBook devices, all of which have cameras and microphones. With a couple of taps, you're connected to your loved ones, and they can see your face via the front-side camera—or switch to the normal camera to chat while you show them the view of your destination. Cost: Free to other FaceTime users. Drawbacks: You can only call others who have the latest Apple gizmos, and it doesn't work with data service—you must be in a Wi-Fi zone.

4) For international road warriors, the best way to call is Toktumi Line2. What do you need? An Android phone, iPhone, or iPod Touch.

Wouldn't it be great to have a U.S. number at which all your clients could reach you even when you're abroad? That's what Line2 gives you—along with visual voice mail, so you won't waste time or money taking calls you don't want. When you're in a Wi-Fi zone, the Line2 app effectively adds a second line to your smartphone, allowing people to call you overseas at no extra charge to them. Cost: The app is just 99 cents, but you'll need to pay $10 a month for a phone number, voice mail, and unlimited calls and texts within the United States; overseas, rates to land and mobile lines start at 2 cents per minute. Drawbacks: See those under Skype, above.

5) Facebook fanatics, the best way to call is Vonage Mobile App for Facebook. What do you need? An Android phone, iPhone, or iPod Touch. 

Vonage's VoIP service has traditionally been marketed as a replacement for home lines, but its mobile partnership with Facebook makes staying in touch on the go as easy as updating your wall. Download the app on your latest-generation iPhone or Android device and it imports contact info for all of your Facebook friends—if they also have the app, you're ready to chat. Cost: Free to other Facebook friends with the Vonage Mobile App. Drawbacks: Do you really want everybody you've friended on Facebook to be able to call you on your mobile?

Smart phones may be getting smarter by the minute, but the sound quality on most of them is far from genius. For crystal-clear audio on phone chats or during your in-flight movie, consider packing Etymotic's HF3 in-ear buds (etymotic.com; $179), or go wireless with Nokia's noise-canceling Bluetooth BH-905i headset (nokiausa.com; $300).