VoIP explained for dummies

In case you did not know, the author of this blog is a developer of VoIP software for embedded platforms. He specialises in call control (SIP/H.323/MGCP) and media(RTP/RTSP) protocols. He has grand plans to contribute towards business development in this technology and make an impact on the lives of people who love to 'talk'. Do not try too hard to guess these protocol names, because it will not really enrich your vocabulary and make a big impact in your daily life. But some of you might find that RFCs make good bedtime stories. Anyway, the communications technology has a plethora of acronyms and I encounter new ones everyday. Other than protocols, voice codecs are the critical components of a VoIP system. Voice codecs (G.711,G.723,G.726 and G.729 are ITU standards) perform compression of digital voice data.

The technology has matured over the last 5 years and products have come of age. They are far more user friendly and readily available. The common VoIP endpoint devices are IPPhones and RGWs (residential gateways). IPPhones are digital phones which directly plug into a LAN connection. However, residential gateways connect to a LAN/ADSL or cable modem provide ports for traditional analog phones. Essentially, the call control protocols establish connections between two users overy the network, and then media protocols transmit your voice signals in the form of data packets. Most VoIP software have very good echo cancellation and jitter buffer algorithms to maintain excellent voice quality.

Voice (and not data) happens to be the biggest revenue supporter for most telecom carriers. The market has reached a tiliting point, where VoIP has gained universal acceptance, and people are dumping their outdated landlines at a fast pace. The biggest benefit to consumers is the cost savings. Gone are days of long distance calls costing a fortune. These days, PC to PC calls are abosutely free and international calls are charged a low price depending of the telecom carrier. In the PC segment, Skype is the universally leading VoIP service provider. In the home phone business, Vonage is the leading residential VoIP service provider in the US. The are several hardware providers like Cisco and TI providing chipsets and networking equipment.

After voice and fax, video phones are the next big technological leap for VoIP. Video phones would basically have webcams connnected to IPPhones or RGWs through USB interfaces. The future of voice communication lies in the emerging standard UMA (Unlicensed Mobile Access) - a combination of 3G mobile communications for outdoor services and VoIP over WLAN for indoor services.