Financial exchanges have begun a move from on-premise and custom-engineered datacenters to the public cloud, accelerated by a rush of new investors, the rise of remote work, cost savings from the cloud, and the desire for more resilient infrastructure. While the promise of the cloud is enticing, the cloud's varying network latencies can lead to market unfairness: orders can be processed out of sequence, and market data can be disseminated to market participants at incorrect times due to varying latencies between participants and the exchange. We present CloudEx, a fair-access cloud exchange, which leverages high-precision software clock synchronization to compensate for noisy network conditions in the public cloud. We also discuss refinements to the CloudEx design that were informed by lessons learned from deploying CloudEx in two academic courses and conclude by outlining future research directions.

We present Juggler, a practical reordering resilient network stack for datacenters that enables any packet to be sent on any path at any level of priority. Juggler adds functionality to the Generic Receive Offload layer at the entry of the network stack to put packets in order in a best-effort fashion. Juggler's design exploits the small packet delays in datacenter networks and the inherent burstiness of traffic to eliminate the negative effects of packet reordering almost entirely while keeping state for only a small number of flows at any given time. Extensive testbed experiments at 10Gb/s and 40Gb/s speeds show that Juggler is effective and lightweight: it prevents performance loss even with severe packet reordering while imposing low CPU overhead. We demonstrate the use of Juggler for per-packet multi-path load balancing and a novel system that provides bandwidth guarantees by dynamically prioritizing packets.

This paper presents a practical approach to rapidly introducing new dataplane functionality into networks: End-hosts embed tiny programs into packets to actively query and manipulate a network's internal state. We show how this "tiny packet program" (TPP) interface gives end-hosts unprecedented visibility into network behavior, enabling them to work with the network to achieve a desired functionality. Our design leverages what each component does best: (a) switches forward and execute tiny packet programs (at most 5~instructions) in-band at line rate, and (b) end-hosts perform arbitrary (and easily updated) computation on network state. By implementing three different research proposals, we show that TPPs are useful. Using a hardware prototype on a NetFPGA, we show our design is feasible at a reasonable cost.

To make networks more reliable, enormous resources are poured into all phases of the network-equipment lifecycle. The process starts early in the design phase when simulation is used to verify the correctness of a design, and continues through manufacturing and perhaps months of rigorously trials. With over 7,000 Internet RFCs and hundreds of IEEE standards, a typical piece of networking equipment undergoes hundreds of conformance tests before being deployed. Finally, when deployed in a production network, the equipment is tested regularly. Throughout the process, a relentless battery of tests and measurement help ensure the correct operation of the equipment.