Why IPTV/IP Video Transport is Different from Data and Voice
Service providers that deploy IPTV services, fundamentally rely on their IP networks to transport live IP Video without loss. Without this basic underlining capability there is no IPTV system. IPTV systems with significant transient loss suffer not just from poor quality with the customer base but significant operational issues in both frustration and cost.
With everything riding on this fundamental responsibility it may be surprising to learn that many IP networks and IP network components that are being used for IPTV transport have never been tested with live video flows.
Some may respond with, so what, these routers and systems have been tested with line rate data generators and have been working in large networks without issue in the past. Isn’t video just high bandwidth data and at worst like higher speed voice traffic?
Why is IPTV/IP Video different?
Live video that is packetized to be transported over an IP network creates a traffic flow with different behaviors and requirements compared to data and voice traffic.
It may also be surprising to learn that in many cases IP Video traffic can cause switched IP devices to experience loss at well under line rate conditions.
The assumptions for QoS that have evolved under IP data transport and to a lesser extent very low bitrate voice flows do not necessarily translate for the higher bitrate IPTV/IP Video flows.
Underestimating the complexity of how network queues handle these new traffic patterns can lead to network designs that build-in systemic limitations that can lead to transient loss events that can plague IPTV/IP Video systems.
Understanding the nature of IP Video is critical to understanding the limits and operations of a well-architected IPTV/IP Video network. This paper will discuss the basic nature of IP Video traffic flows, the issues that these patterns of traffic flows can cause in a switched IP device, measurements that can be used to understand how well a router is performing when carrying IPTV/ IP Video loads and finally a test methodology that can be used to verify and validate switch IP devices and tune their QoS settings.
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