Suburban Area Suburban Area Networks (SANs)Networks (SANs)

Adrian BickerstaffeAdrian BickerstaffeAccess Control and ManagementAccess Control and Management

Supervised by: Dr. Ronald Pose and Dr. Carlo KoppSchool of Computer Science & Software Engineering, Monash University.

OverviewOverview

Anatomy of a SANAnatomy of a SAN Project overviewProject overview The SAN test-bedThe SAN test-bed Access control and managementAccess control and management

– What is it?What is it?– Why is it needed?Why is it needed?– Resource access control.Resource access control.– Node authentication.Node authentication.– Trusted and untrusted nodes.Trusted and untrusted nodes.– Quality of service (QoS).Quality of service (QoS).– Future WorkFuture Work

ConclusionConclusion

Anatomy of a SANAnatomy of a SAN

What is a SAN?What is a SAN?– An ad-hoc, cooperative, wireless, wideband network.An ad-hoc, cooperative, wireless, wideband network.– Self-organising, self-repairing, secure.Self-organising, self-repairing, secure.– Infrastructure owned by end-users.Infrastructure owned by end-users.

First publication by Kopp First publication by Kopp and Pose, 1998.and Pose, 1998.

SAN project team SAN project team expanded to five expanded to five members in 2001members in 2001..

Anatomy of a SANAnatomy of a SAN

Quasi-static topology - combines properties Quasi-static topology - combines properties of dynamic and static networks.of dynamic and static networks.

SAN nodes incorporate RF transceivers and SAN nodes incorporate RF transceivers and network router functionality.network router functionality.

SANs can interconnect home and/or SANs can interconnect home and/or corporate networks and hosts.corporate networks and hosts.

Throughput of tens of Mbits/s.Throughput of tens of Mbits/s. Fault-tolerance and bandwidth aggregation Fault-tolerance and bandwidth aggregation

through redundant paths.through redundant paths.

MotivationMotivation

Telcos’ current broadband subscriber offerings Telcos’ current broadband subscriber offerings provide inadequate performance, reliability, provide inadequate performance, reliability, security and cost-effectiveness.security and cost-effectiveness.

Limitations include:Limitations include:– Asymmetry between upstream and downstream Asymmetry between upstream and downstream

channelschannels– Not available to all customersNot available to all customers– Quality of service inadequate for users’ needsQuality of service inadequate for users’ needs

Potential SAN BenefitsPotential SAN Benefits Provision to the community ofProvision to the community of

– High bandwidth, low cost, secure, flexible, wireless networkingHigh bandwidth, low cost, secure, flexible, wireless networking That is capable of servingThat is capable of serving

– Home-offices, branch-offices, campusesHome-offices, branch-offices, campuses WithWith

– Data, audio, video and other communications independent of Data, audio, video and other communications independent of telcostelcos

ExploitingExploiting– State-of-the-art, off-the-shelf wireless technology with an State-of-the-art, off-the-shelf wireless technology with an

innovative and creative set of custom protocols.innovative and creative set of custom protocols. With the environmental benefits ofWith the environmental benefits of

– No ugly/expensive wired infrastructure, low RF impact due to No ugly/expensive wired infrastructure, low RF impact due to spread spectrum technology, low power consumption.spread spectrum technology, low power consumption.

Innovation and Innovation and CreativityCreativity

An industrial R&D approach.An industrial R&D approach.– Large scale project analyzed and divided into sub-projects.Large scale project analyzed and divided into sub-projects.

SAN project involved the creation of the SAN test-bed SAN project involved the creation of the SAN test-bed as infrastructure to support the design, development as infrastructure to support the design, development and testing of the SAN protocols.and testing of the SAN protocols.

Cooperation/collaboration between team members.Cooperation/collaboration between team members.– All team members involved in overall project design.All team members involved in overall project design.– Independence of sub-projects allows creative approaches whilst Independence of sub-projects allows creative approaches whilst

still contributing to overall project aims.still contributing to overall project aims.– Team members gain high technical mastery of sub-projects and Team members gain high technical mastery of sub-projects and

display thoroughness in communicating their work to other display thoroughness in communicating their work to other team members, supporting the project as a whole, and of team members, supporting the project as a whole, and of course documenting their own work.course documenting their own work.

Project DocumentationProject Documentation

Student thesis included complete, thorough Student thesis included complete, thorough documentation of:documentation of:– All protocols, test-bed H/W and S/W, overall SAN architecture, All protocols, test-bed H/W and S/W, overall SAN architecture,

specific sub-project work.specific sub-project work.– A detailed, thorough literature survey, description of project as A detailed, thorough literature survey, description of project as

a whole and how it relates to other network projects.a whole and how it relates to other network projects. Exceeded 300 pages:Exceeded 300 pages:

– Provides excellent basis for S/W Engineering student who is Provides excellent basis for S/W Engineering student who is continuing with implementation in 2002.continuing with implementation in 2002.

Poster presentation of overall project and sub-projectsPoster presentation of overall project and sub-projects– Allows wider community to understand the project’s Allows wider community to understand the project’s

importance.importance.

Future PotentialFuture Potential

Project encourages further research into:Project encourages further research into:– Comms. protocols, security, QoS, RF signal Comms. protocols, security, QoS, RF signal

propagation, antenna design, environmental propagation, antenna design, environmental issues, RF interference etc.issues, RF interference etc.

Exceptional commercial potential in:Exceptional commercial potential in:– SAN node manufacture, sale/leaseSAN node manufacture, sale/lease– Software development, sale/leaseSoftware development, sale/lease– SAN planning, design and management servicesSAN planning, design and management services– SAN Internet/Intranet gateways and VPNs.SAN Internet/Intranet gateways and VPNs.– Could continue to a start-up company, joint R&D, Could continue to a start-up company, joint R&D,

or a public domain effort.or a public domain effort.

The SAN test-bedThe SAN test-bed

Why the SAN test-bed?Why the SAN test-bed?– A testing and development platform was essential.A testing and development platform was essential.– No development infrastructure existed.No development infrastructure existed.

A SAN is a real-time system, thus:A SAN is a real-time system, thus:– Pure simulation, unless it could run in real time, Pure simulation, unless it could run in real time,

would be unconvincing.would be unconvincing.– A real prototype running at full speed can test A real prototype running at full speed can test

protocol efficiency and correctness.protocol efficiency and correctness.

The SAN Test-bedThe SAN Test-bed

Test-bed hardware:Test-bed hardware:– 20 nodes with wired network interfaces form 20 nodes with wired network interfaces form

a a SAN in a roomSAN in a room..– Homogeneous hardware configuration makes Homogeneous hardware configuration makes

protocol analysis easier.protocol analysis easier.– Thin-wire coaxial cable is a good substitute Thin-wire coaxial cable is a good substitute

for wireless links.for wireless links. Software: Linux for ease of development Software: Linux for ease of development

and portability.and portability.

The SAN Test-bedThe SAN Test-bed

The SAN Test-bedThe SAN Test-bed

Topologies of up to 20 nodes can be simulated.Topologies of up to 20 nodes can be simulated. An example topology…An example topology…

Node A

Node B

Node C

Node D

Node F

Node E

The SAN Test-bedThe SAN Test-bed

……and its representation using the and its representation using the test-bed:test-bed:

Node A

Node B

Node C

Node D

Node E

Node F

Access Control and Access Control and ManagementManagement

Higher level network design.Higher level network design. Controlling which nodes can:Controlling which nodes can:

– access select network resources.access select network resources.– enter a SAN.enter a SAN.– communicate with each other.communicate with each other.

Managing quality of service (QoS).Managing quality of service (QoS).

RoutingRouting

ACMACM

SecuritySecurity

Understanding of other Understanding of other protocols required.protocols required.– Added difficulty to my sub-Added difficulty to my sub-

project.project.

Access Control and Access Control and ManagementManagement

AimsAims

Not all network services may be free (resource Not all network services may be free (resource access control).access control).

Only permitted nodes should be capable of Only permitted nodes should be capable of entering the network (authentication).entering the network (authentication).

Some nodes may not be considered trustworthy Some nodes may not be considered trustworthy by others (trusted nodes).by others (trusted nodes).

Certain resources (e.g. audio) may require a Certain resources (e.g. audio) may require a specific minimum level of QoS.specific minimum level of QoS.

Resource Access ControlResource Access Control

Capability model:Capability model:– Each Each nodenode has a set of capabilities to has a set of capabilities to

access resources.access resources.– Rules must be enforced during operation.Rules must be enforced during operation.

SAN prototype resources:SAN prototype resources:1.1. SAN audioSAN audio2.2. SAN videoSAN video3.3. Gateway dataGateway data4.4. Generic dataGeneric data5.5. Bandwidth (per resource and total)Bandwidth (per resource and total)6.6. AuthenticationAuthentication

Resource Access ControlResource Access Control

Actions associated with Actions associated with each resource:each resource:

NumberNumber ActionAction

00 Give resource propagation capabilityGive resource propagation capability

11 Revoke resource propagation capabilityRevoke resource propagation capability

22 Give resource capabilityGive resource capability

33 Revoke resource capabilityRevoke resource capability

44 Give propagation spread capabilityGive propagation spread capability

55 Revoke propagation spread capabilityRevoke propagation spread capability

Node AuthenticationNode Authentication

The process of verifying that a node is The process of verifying that a node is who it claims to be.who it claims to be.

Important since only authenticated nodes Important since only authenticated nodes can be legitimate SAN participants.can be legitimate SAN participants.

Each node is assigned a serial number Each node is assigned a serial number and authentication key that uniquely and authentication key that uniquely identifies it.identifies it.

Node AuthenticationNode Authentication Authentication procedure for a node first entering a Authentication procedure for a node first entering a

SAN:SAN:

Node C

Node D

Node E

AdminNode S

Node B

1. Serial number and location via, say, telephone.

2. Master authentication capability

3. Supporting authentication capabilities

Secure channel

5. Success / Failure

4. Auth. key

NewNode A

Trusted and Untrusted Trusted and Untrusted NodesNodes

The addresses of all known nodes are The addresses of all known nodes are kept in the routing table.kept in the routing table.

A database records which of these A database records which of these nodes is considered to be trustworthy.nodes is considered to be trustworthy.

Thus, the trusted node database:Thus, the trusted node database:– Enables nodes to communicate only with Enables nodes to communicate only with

those considered trustworthy.those considered trustworthy.– Affects routing decisions handled by the Affects routing decisions handled by the

SAN routing module.SAN routing module.

Trusted and Untrusted Trusted and Untrusted NodesNodes

Only routes formed completely of trusted Only routes formed completely of trusted nodes can be used to send data.nodes can be used to send data.

Trust status does not apply when a node Trust status does not apply when a node forwards data.forwards data.

Upon receipt of data from a global source Upon receipt of data from a global source that is untrusted, an error packet is that is untrusted, an error packet is returned.returned.

Quality of Service (QoS)Quality of Service (QoS)

When the medium is prone to burst When the medium is prone to burst errors, maximising QoS becomes errors, maximising QoS becomes an even greater issue.an even greater issue.

QoS is measured in terms of:QoS is measured in terms of:– Link reliability Link reliability – LatencyLatency– Link utilization (available bandwidth)Link utilization (available bandwidth)– SecuritySecurity

Quality of Service (QoS)Quality of Service (QoS)

An estimate of route reliability and latency on an end-An estimate of route reliability and latency on an end-to-end basis can be requested.to-end basis can be requested.

Links with high error rates can (sometimes) be avoided.Links with high error rates can (sometimes) be avoided. Security levels between nodes are negotiable.Security levels between nodes are negotiable. Data packet size can be adjusted to accommodate Data packet size can be adjusted to accommodate

changing link reliability using either:changing link reliability using either:– Complex formulae.Complex formulae.– Simple heuristics.Simple heuristics.

Using these statistics, links with QoS best suited to Using these statistics, links with QoS best suited to specific needs can be specific needs can be dynamicallydynamically selected. selected.

Future WorkFuture Work

Sub-project future work includes:Sub-project future work includes:

– Testing using wireless network cardsTesting using wireless network cards– Further protocol implementationFurther protocol implementation– Automate responses to possibly malicious Automate responses to possibly malicious

events.events.– Incorporate a charging system into the Incorporate a charging system into the

resource access control component.resource access control component.

ConclusionConclusion

SANs complement existing broadband services offered SANs complement existing broadband services offered by telcos.by telcos.

An industry style R&D approach was taken throughout An industry style R&D approach was taken throughout the project.the project.

Innovation and creativity underlines the SAN Innovation and creativity underlines the SAN philosophy.philosophy.

Student team members each achieved 1st class Student team members each achieved 1st class honours, and are continuing as researchers.honours, and are continuing as researchers.

I have developed:I have developed:– As part of the SAN team: a new and unique network As part of the SAN team: a new and unique network

architecture, along with development infrastructure.architecture, along with development infrastructure.– Individually: access control and management protocols.Individually: access control and management protocols.

Thank YouThank You

Questions?Questions?