Adtec digital RD-30 (version 2.1.1) Manual - Manual (Page 24)

UDP ( User Datagram Protocol ) multicast/unicast streams are commonly used for broadcast transport streams in local or
private networks that contain little to no packet loss. UDP offers no protection against dropped packets or packets received out
of order (usually due to packets taking a different amount of time to traverse network devices). Due to the low reliability of
UDP, it is generally not recommended to be used over the public internet or in environments where the potential of packet loss,
increased jitter, or out of order packets is high. If packets are lost or received out of order, service anomalies will occur.
RTP ( Real-time Transport Protocol ) is another type of multicast/unicast stream that is better to use than UDP in some
environments. RTP is built upon the building blocks of UDP, but adds packet sequence identification. Packet sequencing gives
a receiver the information needed to detect and correct packets that were received ‘out of order’. RTP is highly recommended
when timely delivery of each consecutive packet may not be guaranteed.
RTP + FEC or SMPTE-2022 is an additional method used in dealing with lost packets, where RTP alone can only tolerate packets
received out of order. FEC ( Forward Error Correction ) streams add overhead to the overall data rate, but add protection in
case of a lost packet. FEC ( detection and correction of lost packets ) adds latency and data overhead as opposed to UDP
where no protection mechanisms exist. The amount of packet redundancy and overhead can be configured at the RTP/FEC
transmitter. Each multicast/unicast FEC stream is transmitted on base port N and two FEC streams are sent on N+2 and N+4
respectively. When receiving FEC streams behind firewalls, please bear in mind that two additional ports ( N+2 and N+4 )
must be allowed through for proper error recovery to occur.
The RD-30 supports both unicast (point to point) and multicast (broadcast) streams. How to setup IP addressing and
networking equipment is outside the scope of this document. Please verify that IP addresses and gateways are configured
properly at transmit and receive ends for proper stream reception.
Multicast Reception - Address
To receive a multicast (UDP/RTP/SMPTE2022) stream, place the IP Rx mode to ‘multicast’ and insert a multicast address
desired to receive in the ‘Address’ field. This address must match the same address used on the multicast transmitter.
Multicast IP address ranges are 224.10.xxx.xxx to 239.xxx.xxx.xxx, where 0 <= xxx <= 255. If you are new to multicast and
attempting a first time connection, 226.0.1.1 is a common address to start with. Please verify transmitter address
configuration.
10.29.14- v2.1.1