LDMP Advantages

Why use LDMP (Low-Delay Multi-Path) Reliable Protocol?

  • LDMP can adjust the stream to changing bandwidth. Though Streambox streams use UDP as a transport layer, LDMP is able to adjust the stream based on data from the Decoder (either hardware Decoder or software Media Player). The Decoder sends acknowledgement packets and constantly measures each connection for latency and bandwidth. As bandwidth drops, the encoder reduces the compression quality, reducing its bandwidth needs to compensate.
  • LDMP guarantees consistent latency. LDMP not only measures available bitrate, but round-trip-time latency on each connection. In addition to preserving best quality for the bitrate, LDMP works to maintain a consistent latency for the duration of each stream. Low latency is possible for most connections, but even when it's not, the latency will not increase unexpectedly.
  • LDMP allows the use of multiple connections, even different connection technologies. LDMP utilizes and bonds all available network connections that allow communication with the Decoder. If a connection drops out, LDMP will continue with the remaining connections. If connections are added, LDMP will use them as soon as they are added. Spreading the load over multiple connections will both increase available bandwidth as well as reduce the risk of a stream failure due to a connection problem. LDMP balances the connections according to both bandwidth and latency to produce the most consistent stream possible.
  • LDMP has built-in error correction. Each packet of data sent by the LDMP-equipped Encoder is acknowledged by the Decoder. Packets that are not acknowledged are re-sent by the Encoder, through a different connection if possible. This greatly reduces, and often eliminates, the need for Forward Error Correction, which adds redundant packets by taking bandwidth away from the stream data, and which can be ineffective in variable-bandwidth connections even when large amounts of redundancy are used. Acknowledgement data from the Decoder, though very low in bandwidth (about 2% of the stream bitrate), contains sufficient redundancy to eliminate unnecessary duplication by the Encoder.