Redundancy¶
Hotel TV depends on the channel source, the server, the network and the power supply. Protect each link separately: redundancy in one does not save you from a failure in another.
Backup sources¶
A stream can have several inputs: when the main one fails, the stream switches to the next one by itself, and when the main one recovers, it returns to it (Source redundancy). Typical pairs for a hotel:
a channel from satellite as the main input, the same channel from the internet as the backup;
a channel from the internet as the main input, the welcome video file as the last input: if all sources are lost, the TVs show the hotel’s splash screen instead of a black screen.
Running on a backup input is reported by alert code 27 (input-fallback), a faulty backup input by code 65 (backup-input-error), and a stream without a single working input by code 60 (stream-no-source); all codes are in List of alerts.
Second server¶
Important
Beta version 2.1. What is described here exists only in beta version 2.1: it is installed from the beta repository and only with a licence; the stable version 2.0.2 and the demo edition do not have it. The beta version comes without warranty, and support is best effort (Beta testing programme).
The Meshwork reserve protects against a server failure. Two nodes of the same domain receive the same sources and hold identical outputs to the same multicast addresses, but only one of them sends to each group. If that node, its output or its input fails, the second node picks up the group without a break, and the TVs keep receiving the channels from the same addresses. The nodes can be serviced one at a time: a node that is stopped normally hands over its groups first.
Requirements and configuration are in Reserves. The key points for a hotel:
both nodes are in the IPTV VLAN, and their outputs have the same addresses, ports and egress interface;
in a domain of two nodes, a restarted node does not take over a group straight away; a third node with the reserve switched on, even without channels of its own, removes this wait (Who sends);
both nodes are sized for the full load (Server sizing).
Stable version 2.0.2 has no Meshwork reserve. The second server is kept as a cold standby with a copy of the settings (The pss.json settings file) and is started manually if the main one fails.
Network and power¶
Power. A server with two power supplies on different lines; an uninterruptible power supply for both the server and the switches of the IPTV VLAN: without a switch the TVs are left without channels even if the server is running.
Switch. If there are two nodes, connect them to different core switches of the IPTV network.
Internet. For channels from the internet and for the link to the central headend — two providers or a backup link. Protocols with retransmission (SRT, RIST, PS1) survive short losses on the link; the margin is set by the receiver buffer (Planning bandwidth, latency and ports).
Two paths. Between headend nodes, a single RTP stream can be carried over two independent networks under SMPTE ST 2022-7 (Network requirements for ST 2022-7). The room TVs receive plain UDP multicast, so this does not reach them.
Monitoring¶
Redundancy is only useful if someone finds out about the switchover. Set up alert delivery to the person on duty — by email, to a messenger or to an external system (External alert delivery), and feed the node’s metrics into the integrator’s monitoring system, for example Zabbix or Prometheus (Connecting external monitoring systems).
