QUIC and SPDY Detection - What is It For?

Summary

QUIC and SPDY are expermental protocols created by Google that are not in full common use, however they can cause some unintended classifications on the Exinda

Overview

QUIC (Quick UDP Internet Connection) and SPDY are protocols created by Google in order to try and make various types of connections over the internet faster. QUIC targets UDP connections that aren't offered the same inherent reliability as TCP connections, and SPDY targets latency involved in HTTP communications. Currently, QUIC is only operational in very specific circumstances; the only web servers that will take advantage of QUIC are Google's services, and Google Chrome is the only browser that supports it on the client end. SPDY is a little more universal, implemented in browsers such as Mozilla's Firefox. They work at Layer 4 of the networking stack, adding to TCP/UDP or attaching above HTTP. While these protocols are very good at increasing the speed of internet transfers, they provide their own unique manipulation of packets in order to achieve this.

While the Exinda appliances have definitions for SPDY and QUIC in version v7.4.0 and above, there can be SPDY and QUIC definitions for multiple kinds of traffic which are not differentiated. For example, general 'QUIC' traffic could be showing that it is using a large amount of throughput on the appliance, because someone is accessing Youtube on Google Chrome. Youtube is one of the sites that will allow QUIC to operate very well, as video is a UDP connection. While some of the traffic will still show as Youtube, the actual video stream might have the definition of QUIC, which might not be throttled according to policies that are defined for streaming video.
Furthermore, the problem might arise where QUIC, if put into a streaming video policy which is throttled, will adversely affect behaviour for Google Docs, as Google Docs also can use QUIC.

SPDY is another protocol that can be used by multiple websites in different ways, so being able to put it in the correct policy based on classification is a difficult thing to do.

Exinda is looking at making subclassifications for these general protocols, so that QUIC [Youtube] would be a different application than QUIC [Google Docs]. This is scheduled for a future release.