Singulus G1-T Packet Remapping Application Note - Sponsored Whitepaper

Video over IP technology for the Cable and Telco industries has been born out of 2 well- established technologies: IP packet switching and broadcast digital video. Both of these technologies have well-understood standards for transport and quality, but the blended combination has created a plethora of transport techniques, high expectations, and few established standards.

Despite the lack of standards, a significant number of deployments have been launched with existing and new IP devices for the Video over IP market. Through observation and troubleshooting, an accepted standard of transport for Video over IP seems to be emerging. The two most prevalent transport techniques are seen supporting Video on Demand (VOD) and Broadcast TV over IP. Video on Demand streams are typically unicast UDP/IP flows with video payload that is MPEG2 Transport Stream (ISO 13818). Broadcast TV over IP streams are typically multicast UDP/IP flows with MPEG2 TS payload.

Video over IP flow quality measurements can be divided into three metrics: IP cumulative jitter, packet loss and MPEG TS errors. The Media Delivery Index (MDI) describes the IP cumulative jitter and packet loss rate. The MDI provides an “at-a-glance” indicator of IP transport issues that help separate IP issues from MPEG2 TS issues. The definitions of these Metrics have been developed during troubleshooting and commissioning of Video over IP deployments.

Understanding tolerances for each of these metrics can help separate switched IP issues from MPEG2 TS structure issues. The blending of the metrics between these two technologies has lead to confusion and interoperability issues in the field. Broadcast standards set for MPEG TS may or may not be usable (or even make sense) when applied to an IP infrastructure while jitter and other IP switch router metrics are often misunderstood within video systems. With the fact that in low bandwidth, under-subscribed situations Video over IP works very well, a false sense of durability and scalable quality may be assumed which can be disastrous when scaled to larger deployments. Often larger deployments are launched without ever testing even the simplest of network configurations under fully loaded real world video streams (not to mention other stream types in a converged network).