Reduced latency for real time traffic with SCTP multihoming2016-06-29
In his doctoral thesis, Johan Eklund, lecturer in computer science at Karlstad University,
shows how SCTP and multihoming can be applied to real time traffic. Real time traffic is not only dependent on data being delivered correctly, but also on time.
Different types of real time traffic have different time demands. Some traffic (hard real-time traffic) is strictly dependent on being delivered on time. The consequence of failure in this respect is that the system collapses. In his thesis, Johan studies so called soft real-time traffic, such as IP telephony, streamed real time media and interactive games. The consequences of traffic not being delivered on time is degraded service, which affect the user’s experience negatively.
- Traditional technology like TCP is generally not adapted to real time traffic. SCTP is an alternative transport protocol more adapted to this type of traffic. SCTP offers multihoming,” says Johan Eklund. ”Multihoming means that an end-node can be connected to several networks concurrently. This means that data can be sent via different networks or sent via several networks simultaneously. The reliability increases, but the challenge is to deliver data to the receiving application within the time bound with as low latency as possible.
One of the challenges in multihoming is to handle how the traffic should be sent across the different nets to reach the recipient in the right order. The sender needs to have a scheduler ensuring that each packet is sent via the most optimal network.
- Multihoming offers the potential for a mobile terminal to switch between different types of networks, for example, WiFi and 4G, without interrupting the session and without the user noticing it, says Johan Eklund. Real time traffic is often dynamic and unpredictable. Handling this traffic and meeting the time demands, require dynamic solutions. My thesis involves finding dynamic solutions based on SCTP for this type of traffic,” Johan concludes.