OASIS: Enabling Services with Programmable Networks

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OASIS Enabling Services with Programmable
Networks
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Outline

• Overview
• Introduction to PNEs
• Motivation PNEs and Network Appliances
• Research Opportunities
• Understanding Applications for PNEs
• Programming PNEs
• Our Current Testbed
• Experimental Plan
• QA with Audience

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Overview

• This presentation is a brief summary of our
  whitepaper,
• The OASIS Group at U.C. Berkeley Research
  Summary and Future Directions
• Sahara is focused on services in the network
• The goal of OASIS is to enable new services using
  programmable networks

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Introduction

• A programmable network element (PNE) is a router
  that can perform flexible, complex, and
  application-level computation on packets in the
  fast path

Basic PNE Functionality
OutputPackets
InputPackets
Infer
Classify
Act
State Info
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Classify-Infer-Act

• A server and router in one
• Tight integration between packet processing and
  routing
• High bandwidth (routers) and computation
  (servers)

Infer
Classify
Act
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PNEs The Big Picture

• PNEs are a new technology and present many new
  opportunities
• Were not exactly sure how they will be deployed,
  or what they are useful for!
• Nonetheless, the hardware cost is small and thus
  adding network programmability is basically free

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Network Appliances

• The increasing push towards in-the-network
  processing

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Motivation for PNEs

• Network appliances are generally fixed-function
  devices
• PNEs can consolidate functionality to reduce
  management costs and rack space
• PNEs can be reconfigured to support new
  applications

Firewall
IP Storage Gateway
IntrusionDetector
???
Server Load Balancer
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Motivation for PNEs (cont.)

• PNEs offer the flexibility required to implement
  distributed applications by composition

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PNE Hardware

• PNEs are enabled by silicon and technology
  advances
• Processor arrays, network processors,
  configurable hardware (e.g., FPGAs), specialized
  memories, custom ASIC accelerators, fast and
  cheap storage
• Fast-path computational power
• A modest PNE comprising an array of sixteen
  generic 1 GHz processors can theoretically
  sustain nearly 32,000 instructions per packet at
  1 Gbit/sec (assuming 256-byte packets on average)
• Network processors and custom hardware can vastly
  improve this
• The bottleneck memory bandwidth and state
  retrieval

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State retrieval and management

• (insert picture showing a computation element
  wishing to make a decision based on a large
  amount of previously recorded data)
• (insert picture showing shared, frequently
  updated, frequently accessed resource)
• (insert picture showing packet reordering and
  head-of-line blocking)

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PNE Placement

• Where will PNEs reside in the network? We can
  see applications for virtually anywhere

Access
Edge
Core
Access
Edge
The data rate affects the achievable complexity
of PNE applications
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Research Opportunities in PNEs

• What makes an application suitable for PNEs?
  What are their characteristics?
• What about overlays?
• What is the ideal programming model for a PNE? A
  network of PNEs?
• How do you efficiently handle local and
  distributed state? (Is this a hardware issue, a
  software issue, or both?)
• How do you quantify a PNEs flexibility and
  reliability?

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Applications Suitable for PNEs

• Proposed properties of an application can benefit
  from the programmability and flexibility of a PNE
  when
• the filtering or computation accesses nearly
  every bit in every packet
• The data rates overload a server architecture and
  computational tasks overload a router
• the application is not fully general-purpose
• At least some part of the application has a
  classify-infer-act structure
• the application has geographically distributed
  state that must be quickly aggregated
• a non-trivial conversion between protocols is
  required
• past occurrences affect future filtering and
  computations on flows
• the application changes over time

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Programming PNEs

• A good programming model is critical for writing
  highly reliable and flexible applications
• PNEs require a good programming model for both a
  single-PNE and an ensemble of PNEs
• Our basic single-PNE approach create a router
  virtual machine and program the machine. Apps
  can then be portable and platform-independent
• Basic primitive the generalized packet filter
• Highly flexible and powerful operator
• Uses packet tags to distribute state and
  implement control-flow between virtual machine
  components

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Virtual Machine Example
common configuration
exported VM interface
PNE hardware
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Our Current Testbed
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Experimental Plan

• Expand our testbed!
• Measurement and monitoring a key function of
  PNEs
• In progress prototype of the single-PNE
  programming model on Linux
• Experiment with apps that require distributed
  state
• One possible test application cooperative
  SAN-to-SAN cache

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Overall Research Impact

• Applications will be more reliable and efficient
  by taking advantage of new network services
• Per-flow and per-packet level processing and
  state management will power new forms of
  measurement, monitoring, and actuation
• New understanding for how to manage state and
  processing in distributed, programmable networks

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Audience QA (1)

• What are the key applications for programmable
  networks and PNEs?
• What new apps could make use of the technology?

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Audience QA (2)

• What makes an application ammenable to
  implementation in programmable networks? What
  parts run at the endpoints, and what parts in the
  network?
• Network appliances and proxy applications have
  enjoyed recent success. Build it and they will
  come?
• Is it something about the frequency of
  processing? Stateful processing?
• the filtering or computation accesses nearly
  every bit in every packet
• the application is not fully general-purpose
• the application has geographically distributed
  state that must be quickly aggregated
• a non-trivial conversion between protocols is
  required
• past occurrences affect future filtering and
  computations on flows
• the application changes over time

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Audience QA (3)

• What are the important security and trust issues
  in programmable networks?
• Remember, we are not advocating open,
  instruction in every packet systems ala active
  networks of a few years ago
• Can a network of PNEs be shared between
  (potentially competing) organizations?

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Audience QA (4)

• What is the best way to configure and manage an
  ensemble of PNEs?
• What are the most important issues in terms of
  reliability? (E.g., graphically visualizing a
  configuration?)