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Design of a Home Network

Rajesh Rajamani([email protected])

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Home networking -

Applications

Computer Interconnection

Control

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Home networking technologies

Physical layer

Phoneline

Powerline

Ethernet

Wireless

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We wanted

A Dynamic network

Configuration Sharing resources

Maintanence

Control - from anywhere, anytime

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Design issues

System Software

Hardware

Integrating hardware with software

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Connection Technology

Jini

UPnP

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ChoicesOperating system

Linux

Unix variants

Windows

Guiding principle - Source availability, Synopsysnetwork

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Choices - Hardware

Verilog - Popular in North America

VHDL - Popular in Europe

Guiding principle - Time to Market

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Verification

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Co-verification usingEaglei

Link models

Instruction set simulator (ISS)

Live Target

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GenericVSPRead32()

Eaglei

VSPMemory/registers

1. Function call

2. Reaches VSP core thru eaglei

3. I/O bound instructions are

executed

Link model

Full visibility into the

s/w execution process

Can test functionality

of the design

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ISS model

BFM

ISS

Actual Instructions

Full visibility into the

processor and can

execute assembly instrs

Good for debuggingdevice drivers

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Finally, each device

Application using Jini

JVM

Java Native Interface

Eaglei

Verilog Model

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The Network

The services register their proxies with the lookup

service, which is queried by the servlet for servicing the

request from the client.

DEVICES

WWWCLIENT SERVLET

The Client clicks on the link leading to

his URL requesting a service

Jini

Lookup

1. Ask for

the service

2. Get the

service proxy

3. Interact with device

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Jini Connection Technology

Java centric, distributed system designed for

simplicity, flexibility and federation

Members of the federation agree on basic

notions of trust, administration, identification

and policy

Components - Services, Infrastructure and

programming model

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Components

Infrastructure Programming

model

Services

JVM, RMI,

Discovery/Join,

Lookup service,Java security

Java API,

Leasing,

Transactions,

events

Printer,

Refrigerator,

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Key concepts

Lookup Service - Central bootstrapping mechanism

for the system; helps find and resolve available

services; service added to a lookup service by a pair

of protocols -Discovery andJoin

Leasing - Grant of guaranteed services over a time

period

SecurityJDK 1.2 Security model

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Key concepts

Service object contains the Java programming

language interface for the service, including the

methods that users and applications will invoke toexecute the service along with any other descriptive

attributes.

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Service Provider

Lookup Service

Lookups proxy

Service Provider

Lookup Service

Lookups proxy

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Service Provider

Lookup Service

Lookups proxy

Lookups proxy

1. Get Lookups proxy from the lookup

DISCOVERY

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Service Provider

Service Attributes

Lookup Service

Service Object

Service Attributes

Service Object

Lookups proxy

1. Get Lookups proxy from the lookup

2. Register service object with lookup

Lookups proxy

JOIN

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Service Provider

Service Object

Service Attributes

Client

Lookup Service

Service Object

Service Attributes

3b. Interact with

service

2b. Gets Service

Proxy

1b. Query

the Lookup

service

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Discovery and Join

Discovery - Process by which Jini applications find thelookup services that serve their communities.

Two forms - Serendipitous and hard wired.

Service initiated discovery, Lookup initiated discoveryand direct discovery

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Multicast Request (Service InitiatedDiscovery

Discoverer Lookup Service

1. Request Message(sent via UDPMulticast)IP Address -224.0.1.85 port:4160via UDP Multicast)IP Address -224.0.1.85 port:4160

2. Response Message Service Proxy sent(Sent via TCP unicast)

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Protocol Characteristics

Multicast UDP to IP - 224.0.1.85, port 4160

Interval - 5 secs. Seven rounds of multicast requests is

recommended

Switch over to listening for announcements

Multicast Packet length never to exceed 512 bytes

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Multicast Announcement (Lookupinitiated discovery)


1. Announcements(sent via UDP

Multicast)IP Address -224.0.1.84port:4160

3. Response Message(Sent via TCP unicast)

2. RequestMessage (sent viaTCP unicast)

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Protocol Characteristics

Multicast UDP to IP - 224.0.1.84, port 4160

Interval - 120 secs.

Multicast Packet length never to exceed 512 bytes.

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Unicast Discovery (Direct Discovery)


1. Request Message(sent via TCPUnicast)

2. Response Message(Sent via TCP unicast,connects to 4160)

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Join Protocol

Registering with the lookup service

The service object for the service is loaded into the

lookup service

Get a lease - a period of time during which the leasegrantor ensures that the holder of the lease will haveaccess to some resource

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Join Protocol

Client

Service Object

Service Attributes

Service Provider

Service Object

Service Attributes

Client

Lookup Service

Service Object

Service Attributes

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Lookup Service Specification`

Programs that need a particular type of service canuse the lookup service to find an instance.

Lookup service may provide a set of methods to

enable incremental exploration of the collection.

Users are allowed to explore a collection of itemsdown each of the major axes: attribute value andservice type.

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Lookup Service

Service Provider

Service Object

Service Attributes

Client

Lookup Service

Service Object

Service Attributes

3. Interact with

service

2. Gets Service

Proxy

1. Query the

Lookup

service

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Device Architecture

Alternatives Device with computing power, memory, full JVM

Devices with specialized JVMs - need not includesecurity manager, code verifier, or a number of othercomponents

Clustering of devices with a Shared VirtualMachine

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Full Jini Capable Device

Network

Proxy

Client

Service client

JVM

HardwareImplementation

Service Provider

Communication via RMI protocol

PrivateProtocol

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Clustering of devices with a Jini capable proxy onthe network

Network

Client

Service client Network Proxy


Proxy

JVM

PrivateProtocol

Dev 1 Dev 2 Dev 3

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Conclusions

Encouraging

Easy to put together

Discouraging

Bad response time

Jini + JVM (+ OS) is very heavy

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The Network

The services register their proxies with the lookup

service, which is queried by the servlet for servicing the

request from the client.

DEVICES

WWWCLIENT SERVLET

The Client clicks on the link leading to

his URL requesting a service

Jini

Lookup

1. Ask for

the service

2. Get the

service proxy

3. Interact with device

Refrigerator SmartPhone

Printer

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Finally, each device

Application using Jini

JVM

Java Native Interface

Eaglei

Verilog Model

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Dangerif proxy overrides deserializationmethod

public class HostileFileClassifier2 implements FileClassifier,

java.io.Externalizable {

public void readExternal(java.io.ObjectInput in) {

if (java.io.File.pathSeparator.equals("/")) {// Unix - don't uncomment the next line!

// Runtime.getRuntime().exec("/bin/rm -rf /");

} else {

// DOS - don't uncomment the next line!

// Runtime.getRuntime().exec("format c: /u");

}

}

public void writeExternal(java.io.ObjectOutput out)

throws java.io.IOException{

out.writeObject(this);

}

} // HostileFileClassifier2

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Security - Service

Specify Policy File as command line argument

java Djava.security.policy=filename

Sample Policy File

grant {permission net.jini.discovery.DiscoveryPermission printers";

// multicast request address

permission java.net.SocketPermission "224.0.1.85", "connect,accept";

// multicast announcement address


// RMI connectionspermission java.net.SocketPermission "*.cs.wisc.edu:1024-", "connect,accept";

permission java.net.SocketPermission "130.102.176.249:1024-", "connect,accept";


};

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Security - Client

grant {

permission net.jini.discovery.DiscoveryPermission "*";

// multicast request address


// multicast announcement addresspermission java.net.SocketPermission "224.0.1.84", "connect,accept";

// RMI connections - DANGER

// HTTP connections - this is where external code may come in - careful!!!


permission java.net.SocketPermission "*.cs.wisc.edu:1024-", "connect,accept";


// HTTP connections - this is where external code may come in - careful!!!

permission java.net.SocketPermission "127.0.0.1:80", "connect,accept";

permission java.net.SocketPermission "*.cs.wisc.edu:80", "connect,accept";

};

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Bluetooth v/s Jini

Bluetooth - transport layer, allowing devices

to find each other, to form a local network. It

does not say what they do then

Jini - application layer, allowing services and

clients to use each other

Complementary

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Co-verification

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Clustering of multiple devices (physical option)

Network

Service client


Proxy

Client

Service Provider

JVM

PrivateProtocol

Dev 1 Dev 2 Dev 3

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Leasing Characteristics

A lease is a period of time during which the leasegrantor ensures that the holder of the lease will have

access to some resource

A lease holder can request that a lease be renewed.If not renewed, the lease simply expires

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