What is IPTV system?
IPTV system is a set of hardware equipment and software interconnected via a computer network and intended to provide video content to viewers. Streamers, Encoders, Middleware, Video-on-demand, Time-shift and other components are forming together a well-balanced system that is providing IPTV service to hundreds and thousands of users over local metro-e networks, FTTh optical cable or even mobile LTE and WCDMA networks.
Besides the technical questions it is important to take care of local law requirements, which sometimes are literally shaping some parts of an IPTV systems. For example, in developed economies the copyright is treated very seriously with law enforced regulations for conditional access systems that has to be integrated all the way down from content providers, to IPTV service providers, network providers and client devices.
To conclude, an IPTV system is very complex and has to be designed with best practices of system architecture design and software development methodologies to be efficient and reliable, while conforming to all law requirements. Please find a more detailed explanation of an IPTV system in the article How an IPTV TV System compares to Cable, Satellite, and OTT.
What is an IPTV server?
Any IPTV solution has core part which receives channels, stores content and manage user access. The IPTV server usually consists of several physical servers, divided by the function they perform. Streamers, Middleware, Video-on-demand and other servers are connected together to create one IPTV system. Some solutions combine all components in one server, this is suitable for small installations but could limit system performance and services. For better service availability and easier system reconfiguration it is more suitable to use IPTV system with modular architecture spread across several servers.
How does IPTV server work?
Most IPTV servers are hosting Linux OS with IPTV-specific applications installed.
- Media streamer
This part usually controls the acquisition of media content from cable, satellite or antenna, AV or HDMI encoders and IP streams. Received content is then routed as IP packets to an IP address, from which client devices can receive the content. Depending on signal type and streamer specifications, streamer can filter PIDs, decrypt or otherwise process the content.
This is where client devices get their service information provisioned from. This would include tariff-specific channel list, EPG information, available content and services.
VoD server is a storage for media files like movies, video clips etc. It must provide secure and flawless access to stored content, based on what is allowed to be accessed to a specific user.
- Other applications
IPTV uses IP networks with incalculable diversity of equipment which may become unstable enough to flip from working smoothly to a complete denial of service. In order to prevent services from rendering unavailable, various background services are monitoring the Quality-of-Service to warn administrators of possible issues before users notice something and start complaining to technical support.
All IPTV server apps communicate with each other and with client devices in order to form an IPTV system. Common sequence of retrieving video streams includes a client device that authenticated on Middleware server with subscription plan attached. Middleware then sends list of channel and other content that is allowed to be accessed for certain conditions like balance, tariff plan, purchased or leased movies etc.
When user selects a channel or clicks on a movie, the client device will request the video stream from IPTV server. A stream of IP packets with encoded video, audio, subtitles and other info is then delivered via one of network protocols. The client device only needs to decode the information and represent it on the screen, play through dynamics etc.
Sometimes the process is a little bit more complicated, especially when a conditional access system is protecting the content. But from user perspective this will not affect the experience, while client device will decrypt the content in real time as it is downstreamed.