SMPTE ST 2022-7 is the standard for protecting a video stream against data loss by seamlessly switching between two incoming streams.
The standard, sometimes also referred to as SIPS, uses two identical streams of packets. The streams are sent using RTP, a protocol which adds a sequence number to each packet prior to sending. This means the receiver should find itself presented with two identical streams, often sent over two paths. When one stream loses a packet, the receiver uses the sequence number to pick out the lost data from the other stream. A small buffer is added to the receiver to allow it time to do this, typically of the order of 20ms for good streams, though it's important to compensate for any difference in latency of one path over the other.
ST 2022-7 differs from FEC in two ways, whilst FEC can also seamlessly cope with some packet loss in a stream, ST 2022-7 protects against loss of a whole path as well. It can also cope with any type of outage whether it be long periods of no traffic or many random bursts whereas FEC is designed to only cope with certain failure modes. FEC is best used when only a single stream is possible when adding up to 25% of extra data is a good compromise for protecting the stream.
ST 2022-7 is widely used in broadcast as it is very powerful and provides true, seamless protection for any RTP feed, whether uncompressed ST 2022-6, ST 2110-20/30 or compressed MPEG.