Enhancing Packet Trimming Behaviour for Programmable Protocols

One of the recent methods for effectively utilising the available bandwidth of the network as conditions change is in-network packet trimming. It has advantages for applications which rely on low-latency and low-loss, such as video streaming. Packet trimming allows a network node to reduce the size of packets as they travel across the network, by removing some of the content, during the journey of each packet. In our previous work, we presented a system for layered SVC video streaming, and showed how the trimming process can be successfully implemented and utilised as a virtualized edge deployed function. If trimming is needed, there is a task which has to unpack all the video content and meta-data, including associated significance values, then determine which data to remove, and finally repack and rebuilding a new packet. Conversely, a simple scheme for packet trimming, in the form of a basic buffer cutting process, has been implemented in switches. This process keeps the first bytes of a packet, and drops the rest. Here we investigate if a buffer cutting process can be used for layered video, and describe the issues arising and the design aspects needed to adapt from packet rebuilding to packet cutting.