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OASIS: Enabling Services with Programmable Networks

George PorterMel TsaiLi Yin

Randy Katz

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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 Q&A 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

ClassifyClassify ActActInferInfer

State InfoState Info

Basic PNE FunctionalityInputPackets

OutputPackets

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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)

IP

TCP

HTTP

iSCSI

FCIP

MPLS

Ethernet

ATM

…?

Intrusion Detect

NAT

Store/Ret. State

TCP/IP lookup

Checksum

Count/Tag

…?

Error Detect

Drop

Route

Load Balance

Replace Fields

Resize Pkt

Encrypt

Forward

Compress

…?

Classify Infer Act

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PNEs: The Big Picture PNEs are a new technology and present many

new opportunities

We’re 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

F5 Networks BIG-IP LoadBalancerWeb server load balancer

Packeteer PacketShaperTraffic monitor and shaper

Ingrian i225SSL offload appliance

Network Appliance NetCacheLocalized content delivery platform

Nortel Alteon Switched FirewallCheckPoint firewall and L7 switch

Cisco IDS 4250-XLIntrusion detection system

Cisco SN 5420IP-SAN storage gateway

Extreme Networks SummitPx1L2-L7 application switch

NetScreen 500Firewall and VPN

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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

FirewallFirewall

IntrusionDetector

IntrusionDetector

Server LoadBalancer

Server LoadBalancer

IP StorageGateway

IP StorageGateway

??????

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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…

Core

EdgeAccess

Edge Access

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 PNE’s 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

PNE hardware

common configuration

exported VM interface

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Our Current Testbed

server1

Passport

Alteon

iSD

eth1169.229.48.246

eth010.0.0.1

VLAN 5

VLAN 4

ethernet 4/8

ethernet 4/3ethernet 4/2

ethernet 3/310.0.0.127 / 24

10.10.140.1 / 24

Default VLAN (all ports)

10.10.140.200 / 24default gw = 10.10.140.1

10.10.140.3

eth1

client03

10.0.0.103

eth0

clientserv04

10.0.0.104

eth0ethernet 3/5

ethernet 3/1

client01

10.0.0.101

eth0

windows1

10.0.0.100

eth0

eth110.2.2.104

Accelar Switch

client05

10.2.2.105

client06

10.2.2.106

client07

10.2.2.107

client08

10.2.2.108

“Private” Clusteron 10.2.2.x

client02

10.0.0.102

eth0

ethernet 3/7

Default VLAN (all ports)

10.2.2.1 / 24

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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 Q&A (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 Q&A (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 Q&A (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 Q&A (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?)