VUE allows you to optionally enable or disable transport stream redundancy (TSR) on an input transport stream. VUE allows you to select the primary and secondary TS parameters using the EM. You can apply input transport stream redundancy on MPTS and PID stream inputs on UDP, passthru, automap, and PID mappings. You can select the input transport streams for TSR that are received on bonded pairs of interfaces. This means you can select and identify an interface from which you can receive a TS that may be a bonded (paired) interface. The TSR screen on the EM is automatically updated based on the chosen interfaces. A primary or secondary input TS can not be used within another entry as a secondary or primary TS, respectively, on the same application server. Multiple Transport Streams can have different or same input mappings.
The Mappings screen indicates the corresponding mapping status. The Input In Use column indicates primary/secondary input and display the corresponding values in Input Multicast and Input Source columns.
An input transport stream is backed up by a secondary input transport stream. It is assumed that both transport streams contain the same compliment of MPEG services and/or ancillary (unreferenced) PIDs. The PID values used between secondary transport streams can be same or different as they are discoverable using the PSI. However, if a secondary input TS does not contain one or more MPEG services/ancillary PIDs, which have been successfully mapped to an output for the primary TS, VUE shows waiting for service error for the missing services.
Because the TSR feature is hot_cold based, there will only be one active instance of any redundant TS input. Hence, VUE supports TSR up to the capacity of transport streams and PID streams supported by the VUE application server (for example, 960 transport streams). If the primary input fails, VUE automatically fails over to the assigned alternate input stream on the same or alternate interface. VUE also ensures that when the standby server becomes active, it uses the exact same receive network parameters as the failed initial active server to receive input transport streams (TS).
VUE supports auto-fallback of TS redundancy. VUE server automatically attempts to switch back to the primary TS if while receiving from the secondary transport stream it subsequently fails. You can enable auto-fallback in the TS Redundancy AutoFallback field in the System screen on the EM. If auto-fallback is enabled, VUE attempts to switchover to an alternate input transport stream because of a detected failure, but it is unable to acquire the alternate input stream, the VUE continues to try both primary and secondary streams until one of them is successfully acquired. If disabled, the VUE automatically transitions once from primary to secondary TS requiring. You may have to manually force a fallback to the primary TS if the secondary TS subsequently fails. For more information, see Perform forced failover on TS redundancy.
TS failover triggers
- If the bit rate of the
primary input TS drops to 0 Mbps for multicast session timeout period. The
default timeout is 5 seconds (Range 600 ms – 6000 ms).NOTE: PSI is not considered as part of the bit rate determination as the A/V component streams could be lost at the input to an upstream encoder/mux that is continuing to transmit PSI downstream to the VUE.
- All input transport streams
received on a particular NIC failed, if the link of the NIC is lost or if
the interface fails. NOTE:
If bonded interface is being used, then both sides of the bonded group must fail to declare the interface failed.
If an input interface is bonded (composed of two paired Ethernet interfaces) and only one side (interface) of the bonding group fails, VUE does not consider that as a failed interface. VUE continues to receive transport streams from the functioning side of a bonded interface without triggering a failover to the alternate interface associated with the TSR group.
- VUE can consider to include null packets or exclude null packets when measuring a transport stream’s input bit rate.
- Removes the mappings associated with the failed TS.
- Re-establishes every mapping that was affected by the loss of the primary input transport stream. IE, if there were multiple UDP mappings taken from the same TS and multiple ancillary PID mappings, these same mappings shall be re-established for the alternative input TS.
- Issues a multicast group join (IPv4 GMP Join) for its backup MC Group Address, and IP Source if enabled for SSM, on the secondary interface configured.
- Adapts to any input PSI differences between the primary and secondary input transport stream, including different PMT PID references within the PAT, different component PIDs referenced by the PMTs, and so on.
- Maintains the same output MPEG Service Number (SN) if they had changed from input to output.
- Completes the transition, which includes the time for declaring an input TS failed, changing the mapping, issuing the join and starting the flow of newly acquired TS into the output transport stream (OTS).
For more information about how to manage TSR, see View, edit, and delete transport stream redundancy.