Headend to home
Encoders prepare live and VOD assets; middleware provisions entitlements; STBs or smart-TV apps decode streams protected by DRM licenses.
Multicast vs. unicast
Carrier IPTV often conserves backbone bandwidth with multicast; pure OTT relies on CDNs and per-user manifests—each model has capex trade-offs.
Viewer expectations
Instant channel zaps, replay windows, and cross-device pause states require orchestration APIs that legacy cable stacks never imagined.