Jargon busting: P2P and VoIP

Both 'P2P' (short for 'peer-to-peer) and 'VoIP' (or voice over IP) were in the news this week. Two top analysts earmarked the practices as internet services that could become premium brand earners for mobile broadband providers in the near future. The use of these services could be added as extras to a mobile broadband package, rather than being included as standard. However, for casual internet users, P2P and VoIP may not be familiar terms. So what do they mean?

P2P

Peer-to-peer computing, or P2P, is a way of linking computers together to share files via the internet. Presently, the most common usage is to share music, gaming and video files, often without permission from the copyright owners. It is an area that is generating huge debate, especially within the music industry, as record companies see their sales being ravaged by illegal downloading; there has even been calls for a broadband tax to help pick up some of the losses the music industry is experiencing. 

Essentially, P2P works by letting users download a programme from the internet that can be used to search for content, and then manage the downloading of files. The practice grew in notoriety when the Napster network, operational between 1999 and 2001, grabbed the headlines when sued by record label A&M for 'contributory and vicarious copyright infringement' in the US. Napster used central files to store lists of the files available on its network, so it was not a pure P2P service, but the principal was the same: users looked for a a song, album, film etc, and then downloaded it from others across the world who had it on their machine to share. Napster lost the A&M case and, being unable to block access to infringing material, closed down in 2001. At its peak, Napster verified user numbers upward of 26.4 million worldwide.

More recently, computer programs such as Vuze and Bitcomet have become the P2P tools of choice, letting users share 'torrents' - computer files transmitted by a client program using the BitTorrent protocol. BitTorrent technology makes downloading faster by breaking up each torrent (such as a film or album) into small parts and searching for them from a number of computers at once, before rebuilding them as the original file on completion. While similar to Napster as far as legality, the difference is that BitTorrent programs do not store file information; they merely introduce computers with the same files by searching for them, making it difficult for companies to sue them. 

The popularity of torrents for sharing films, music and gaming, as well as other computer files, has reached epidemic proportions; some estimations have put the total at 35 per cent of all internet traffic. Of course not all of it is illegal traffic; many companies use the technology as a legitimate file sharing tool, including Blizzard, the makers of online game World of Warcraft, which has more than 11.5 million subscribers worldwide. The actual total figure for all P2P traffic has been estimated at closer to 70 per cent in recent years by CacheLogic; a staggering figure.

VoIP

VoIP is short for 'voice over internet protocol'  and is the term used for telephone transmissions made via the internet, instead of through traditional telephone wires or mobiles; other terms you may hear that mean the same thing are 'internet telephony', 'voice over broadband' and 'internet phone'. Voices are converted into data and passed via digital signal, commonly via computer, as regular internet traffic.

One of the most common names in VoIP, especially when it comes to broadband, is Skype. The software is free to download onto your computer and can then be used to make free digital telephone calls, via your computer (so you need a headset or microphone), to any other Skype users in the world. At the end of 2008 Skype claimed to have 405 million accounts worldwide, which have clocking up more than 20 billion Skype-to-Skype minutes.

As well as computer-based software, you can also purchase dedicated standalone cordless internet phones that do not need a computer to choose (such as 3's Skypephone). Another example is BT's top end broadband 'Home Hubs', which have a VoIP handset attached, although these are subject to (normally reduced) BT call charges. The third way to access a VoIP connection is via an 'analog telephony adaptor'; a power adaptor that takes standard telephones in at one end and plugs into your internet connection at the other. 

The problem is that VoIP traffic is very bandwidth intensive, and the lure of free calls means it is becoming increasingly popular. When you bear in mind that your average broadband (such as BT and Virgin Media) or mobile broadband provider (such as O2 and T-Mobile) earn most of their profits through voice minutes, it's hardly surprising they are thinking of banning it from their internet packages!