Embodiments are directed to systems and methods for delivering broadcast
television (TV) using an Internet Protocol (IP) network. The IPTV system
and methods use real-time routing servers to unicast and/or multicast of
broadcast television programs. The IPTV system and methods may enable
advertisers to insert local commercials into national or international
television broadcasts. The IPTV system and methods offer network-based
time-shifting of broadcast television programming rather than personal
video recorder (PVR)-based time-shifting. The IPTV system and methods may
provide scalable video on-demand (VOD) by multicasting video content and
dynamically determining whether to speed up or slow down a bit stream to
catch up to or wait for the previous or next multicast of the video
content. The IPTV system and methods also may enables interactive
television programming whereby a viewer may be permitted to exchange
video with a television program and have that video displayed.