Naga Praveen Katta

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A <i>consistent update</i> installs a new packet-forwarding policy across the switches of a software-defined network in place of an old policy. While doing so, such an update guarantees that every packet entering the network either obeys the old policy or the new one, but not some combination of the two. In this paper, we introduce new algorithms that trade(More)
Software-defined networking (SDN) offers greater flexibility than traditional distributed architectures, at the risk of the controller being a single point-of-failure. Unfortunately, existing fault-tolerance techniques, such as replicated state machine, are insufficient to ensure correct network behavior under controller failures. The challenge is that, in(More)
Software-Defined Networking (SDN) enables fine-grained policies for firewalls, load balancers, routers, traffic monitoring, and other functionality. While Ternary Content Addressable Memory (TCAM) enables OpenFlow switches to process packets at high speed based on multiple header fields, today's commodity switches support just thousands to tens of thousands(More)
Software-Defined Networking (SDN) allows control applications to install fine-grained forwarding policies in the underlying switches. While Ternary Content Addressable Memory (TCAM) enables fast lookups in hardware switches with flexible wildcard rule patterns, the cost and power requirements limit the number of rules the switches can support. To make(More)
Modern computer networks perform a bewildering array of tasks, from routing and traffic monitoring, to access control and server load balancing. Yet, managing these networks is unnecessarily complicated and error-prone, due to a heterogeneous mix of devices (e.g., routers, switches, firewalls, and middleboxes) with closed and proprietary configuration(More)
Datacenter networks employ multi-rooted topologies (e.g., Leaf-Spine, Fat-Tree) to provide large bisection bandwidth. These topologies use a large degree of multipathing, and need a data-plane load-balancing mechanism to effectively utilize their bisection bandwidth. The canonical load-balancing mechanism is equal-cost multi-path routing (ECMP), which(More)
In-band Network Telemetry (INT) is a new abstraction that allows data packets to query switch-internal state such as queue size, link utilization, and queuing latency. We prototype INT in the recently proposed P4 language using a software switch as the implementation platform. We then show how INT can be used to diagnose performance problems such as(More)
Software-Defined Networking (SDN) allows control applications to install fine-grained forwarding policies in the underlying switches, using a standard API like OpenFlow. Highspeed Ternary Content Addressable Memory (TCAM) allows hardware switches to store these rules and perform a parallel lookup to quickly identify the highest-priority match for each(More)
Multi-tenant datacenters predominantly use equal-cost multipath (ECMP) routing to distribute traffic over multiple network paths. However, ECMP static hashing causes unequal load-balancing and collisions, leading to low throughput and high latencies. Recently proposed alternatives for load-balancing perform better, but are impractical as they require either(More)