Some subscribers cannot receive IPTV services over DSL because they are too far from the central office. Joachim Roos, CEO of Edgeware explained to me at the TelcoTV trade show that while the DSL service may acceptable for Internet service, the packet loss is too high for IPTV. Even a 2% packet loss can result in poor IPTV quality. This makes both the subscriber and the service provide unhappy. The good news is that there is an open standards retransmission process (RFC 4588) that allows lost IPTV packets to be retransmitted by a cached video server. This allows a service provider to extend the maximum distance of IPTV service for subscribers. It can be better to retransmit IPTV video through a distributed video delivery network.
This video shows the distortion that occurs when 2%, 10%, and 20% packet errors with and without retransmission: