ory with residential voice services, fear that competition is eroding the number of access lines being deployed, and fear that traditional land- line revenues will continue to fall even further. IPTV therefore holds great promise for telcos. But more importantly, with IPTV, telcos and cable providers alike can offer triple-play services. It is also important to note that IPTV is not just a replica- tion of the passive cable TV viewing environment of old; instead, it offers services including interactive gaming, access to massive libraries of video content on demand, and e-commerce activities, with a view to future features such as energy management and security services. IPTV was not possible in the dialup era, when the download speeds were far too slow to allow any type of video content to be received, let alone enjoyed. With the penetration of broadband growing daily, IPTV is becoming available to more households. The market research firm Research and Markets expects the number of global IPTV subscribers to grow from 4.3 million in 2005 to 36.8 million in 2009, at a compound annual growth rate of 72%. Europe is leading the market for subscriber numbers, while Asia and North America have fallen off slightly due to a slower-than-expected rate of fiber deployment ("Global Users Tune In to IPTV," www.vnunet.com/vnunet/news/2154560/iptv-set-rocket). Needless to say, many if not most of the world's leading telecom providers are investigating IPTV, in the search for a new revenue-generating opportunity and as a defensive measure against the ever-increasing encroachment of cable TV operators. Because IPTV relies on IP, it promises lower costs for providers and lower prices for consumers-what appears to be a win-win situation. IPTV supports both live TV (multicasting) and VOD (stored video). IPTV is viewed on a TV and requires a set-top box. The video content is usually in MPEG-2 TS (Transport Stream) format, delivered via IP Multicast. IPTV was specifically designed to deliver high-quality content to a traditional TV t