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Exploring a Framework for Developing the Future

Internet: Lessons from the Y-Comm

ArchitectureGlenford Mapp

Principal Lecturer, Middlesex University

PURSUIT 2011 Computer LabComputer Lab

Outline of the Talk

• Motivation for the work

• Our approach

• Introduction to Y-Comm

• Peripheral Framework

• Areas of Work

• Conclusions


Motivation (looking backward)

• Originally we started with ubiquitous handover. – Fore-runner was work on the Cambridge

Wireless network which looked how you do handover between different wireless systems

• James Scott, Leo Patanapongpibul, Pablo Vidales

– YComm ended up looking at ubiquitous handover, Quality-of-Service, Security and Application environments/Service Platforms


Lesson -1.0• Each of these are big areas in themselves

– Can study each area on its own and that is what a lot of people are doing.

• End up with good papers but not something that you could take and build a real system

• We took the opposite viewpoint. – Try to describe the big picture first

• Develop the mechanisms but keep always keep the big picture in view


Lesson -0.5

• Don’t be foolish– Invent things only when you need to

• Y-Comm is not trying to invent new technologies for the sake of it

– Use standards or new technologies

• Be futuristic– Take a guess but realize you could be wrong– Allow evolution– Be conservative


Futuristic Assumption 1: Network Evolution

• The Internet will evolve in a physical sense• Core of the network

– Super-fast backbone (optical switching, etc)– Fast access networks (MPLS, ATM)

• Peripheral Wireless Networks– Errors due to fading, etc; not just congestion– Handover

• Consequences• Degradation of end-to-end arguments

PURSUIT 2011 Computer LabPURSUIT 2011

Internet Evolution

BACKBONE

ACCESS NETWORKS

WIRELESS NETWORKS


Futuristic Assumption 2: Heterogeneous Devices

• Devices will have more than one wireless interface.

• Vertical handover – switching between different network interfaces to provide seamless connectivity

• Vertical handover is good but it introduces a lot of QoS issues because the different wireless networks have different qualities of service


Vertical Handover (Sideffects)

• Affects your connections – Some protocols react badly with respect to

handover.

• Affects your applications– Need to think through how Quality-of-Service

affects applications

• Encapsulate these ideas in a Framework


Layer 5: Slow Adaptation of TCP After LAN->GPRS Handover


Lesson 0.0• New framework

– We need to control network interfaces generically

– Make mobility support explicit• Vertical handover can have tsunami effects

– Merge network and transport services – Make QoS support explicit

• Provide a way for applications to negotiate with the network


The Complete Y-Comm Framework

HARDWARE PLATFORM (MOBILE NODE)

HARDWARE PLATFORM (BASE STATION)

NETWORK ABSTRACTION (MOBILE NODE)

NETWORK ABSTRACTION (BASE STATION)

VERTICAL HANDOVER

POLICY MANAGEMENT

END SYSTEM TRANSPORT

QOS LAYER

APPLICATION ENVIRONMENTS

(RE)CONFIGURATION LAYER

NETWORK MANAGEMENT

CORE TRANSPORT

NETWORK QOS LAYER

SERVICE PLATFORM

CORE NETWORKPERIPHERAL NETWORK

SAS

NTS

NAS

QBS


Y-Comm Group• Middlesex University

• Mathematical modelling of vertical handover (TBVH) and the Stream Bundle Layer for Downward QoS (Fatema Shaikh)

• Transport protocol and network architecture issues in Peripheral networks (Glenford Mapp)

• Security (Mahdi Aiash)• Mobile Services (Fragkiskos Sardis)

• University of Cambridge• Proactive knowledge- based policy mechanisms for

handover (David Cottingham)• Networking issues (Jon Crowcroft)


Y-Comm Group• University of Sao Paulo (ICMC San Carlos)

• Ontological services for vertical handover• SoHand Middleware (Edson Moreira and Renata Vanni)• Core Network Management (Mario Augusto)

• Federal University of San Carlos• Testbed based on IEEE 802.21

• Loughborough University• Security Framework in Y-Comm (Raphael Phan)


This talk

• Can’t explain everything about Y-Comm • It’s too big

• Concentrate on the Peripheral Network

• See Y-Comm Research Webpage:

• http://www.mdx.ac.uk/research/areas/software/ycomm_research.aspx


The Peripheral Framework

APPLICATION ENVIRONMENTS LAYER

QOS LAYER

END TRANSPORT SYSTEM

POLICY MANAGEMENT LAYER

VERTICAL HANDOVER LAYER

NETWORK ABSTRACTION LAYER

HARDWARE PLATFORM LAYER


Layer 1: Hardware Platform Layer

• Hardware Platform Layer– Defines the physical requirements for a

particular wired or wireless technology– Expanded physical layer

• Includes electromagnetic spectrum• Modulation and channel reservation algorithms

– Incompatibility issues• Two technologies may be incompatible and cannot

be used simultaneously


Hardware Platform Layer Represented as Vertical Components

3G WLAN 802.11

WiMax802.16

UltraWideBand


But all this is about to change!

• Need to make more efficient use of the electromagnetic spectrum

• Cognitive Radio– A radio that is aware of and can sense its

environment, learn from its environment, and adjust its operation according to some objective function


Cognitive Radio (CR)• Technology

– Software Defined Radio (SDR) • Wide spectrum receiver• Do the processing in real-time

– Intelligent Signal Processing (ISP)• Allows it to detect interference and move to another part of

the spectrum

– Ideal cognitive Radio – Mitola Radio > 2030• Mitola radio uses CR as the physical layer of a

communications model• That’s why CR is part of Y-Comm


Cognitive Radio

WIDE SPECTRUM REECIVER

SOFTWARE DEFINED RADIO

SPECTRUM MANAGEMENT

3G WLAN WiMax

INTELLIGENT SIGNAL PROCESSING

UltrawideBand


Layer 2: Network Abstraction layer

• Network abstraction Layer– An abstraction that allows us to define, control

and manage any wireless network on a mobile host

– Key issues: data path functions; data formats (Link-layer), turning features on and off

– Need to generate L2 triggers when a new network is detected or when an old network is no longer detectable

• Build on 802.21

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802.21: Key Services

Link Layer TriggersState Change

PredictiveNetwork Initiated

Network InformationAvailable NetworksNeighbor MapsNetwork ServicesHandover Commands

Client InitiatedNetwork Initiated

Vertical Handovers

802.21 uses multiple services to Optimize Vertical Handovers

802.21 MIH Function

Protocol and Device Hardware

Applications (VoIP/RTP)

Connection Management

WLAN Cellular WMAN

L2 Triggers and Events

Information Service

Mobility Management Protocols

Smart Triggers

Information Service

Handover Messages

Handover Management

Handover Policy

Handover Messages IE

EE

80

2.2

1IE

TF

802.21 Overview


Layer 3: Vertical Handover Layer

• Layers that define the mechanism for vertical handover.

• Support for different types– Network-based – Client-based


Client-Based Handover

• More scalable for heterogeneous networks– Mobile node can monitor the status of all its

network interfaces via the network abstraction layer

– Can take into account other factors such as the state of TCP connections

• Don’t want to do a handover during the start and termination of TCP connections


Lesson 1.0 handover is complicated

HANDOVER

IMPERATIVE ALTERNATIVE

REACTIVE PROACTIVE

KNOWLEDGE-BASED MODEL-BASED

NETPREF

USERPREF CONTEXT

SERVICES

UNANTICIPATED ANTICIPATED


Layer 4: Policy Management layer

• Decides if, when and where vertical handover should occur.

• Must be able to deal with all cases of handover– Reactive done– Proactive – most favourable but hard


Reactive Policy: PROTON

HANDOVER EXECUTION LAYER

INPUT/OUTPUT LAYER

POLICY LAYER (PONDER)

WLAN GPRS LAN

L2 Triggers

HIGHER LAYERSInterface Information


Layer 4: Proactive Policies

• Proactive Policy Management– The mobile node can know or estimate the network

state at a given point before it arrives at that point– Proactive Policies allow us to maximize the use of

available channels provided you know the amount of time a channel will be available.

– That time is known as: • Time before vertical handover (TBVH)• Can significantly reduce packet loss during all vertical

handovers


Layer 4: Proactive policies

• Proactive policies can themselves be divided into 2 types

• Proactive knowledge-based systems– Knowledge of which local wireless networks

are operating at a given location and their strengths at that point

– We also need a system to maintain the integrity, accessibility and security of that data


Proactive Policies

• Knowledge-based approach

• Gather a database of the field strengths for each network around Cambridge

• Need to maintain the database and also know how the results might be affected by seasonal effects


Knowledge-Based Policy Management (Cambridge)


Proactive Policies – Modelling Approach (Middlesex)

• Using a simple mathematical model• Define a radius at which handover should

occur• Find out how much time I have before I hit

that circle, given my velocity and direction• Calculate TBVH

• Used simulation (OPNET)• Can be used in the real world as well as in

simulation


The Model-Based Handover

Threshold Circle coverage

Real coverage

Exit coverage

Exit threshold circle

Handover threshold circle


Predictive Mathematical Model for TBVH(Simple Case)

• Introduction of additional functionality to Base Station at network boundary (BBS).

• Distance between MS and BBS derived from location

co-ordinates or

• Estimated TBVH

)log(10 lRSSdB

v

xdxdrTBVH

cossin 222

Movement of MS under BBS coverage (upward vertical handoff)

BBS

MS

r

dz

x


Simulation and Results

TBVH simulation in OPNET Modeler:


A

B

C

S

T

NET A

NET B

NET C

Combining Transport and Communications to determine the optimum handover


A

H1

C1

C2B

Y1Z1

E1

Y2

Z2

C

Y3

Z3

H3

E2

E3

S

TH2

Analysis shows that it is possible to calculate these key points with some degree

of accuracy


This is getting interesting

• Because we can not only work out TBVH

• You can also calculate the amount of time a mobile node will be in a given network

• Try to optimize handovers when networks overlap– Depends on the velocity (affects the exit

radius) and adaptation time


Vertical Handover

POLICY MANAGEMENT LAYERDECISION HANDOVER

(BASE-STATION, 3G, QOS, TBVH)

GPSLocation,

Speed, direction

Connections (QoS)

VERTICAL HANDOVER LAYERACQUIRE RESOURCES

( 3GCHAN, BASE-STATION, QOS)

NETWORK MANAGEMENT LAYERSend to Mobile

TOPOLOGY, RESOURCES, QoS

TBVH New QoSNew IP

RECONFIGURABLE LAYERACQUIRE CHANNEL

(3G, BASE-STATION, QOS)

NETWORK ABSTRACTION LAYERBASE-STATION

CHANNEL ACQUIRED

DO IT

NETWORK ABSTRACTION LAYERDATA CHANNNEL = 3G

3G=ACTIVE WLAN=PASSIVE WiMAX= PASSIVE

3G WLAN WiMax 3G WLAN WiMax

Done

DO IT

L2 eventsMedia Info

CORE NETWORKPolling


Lessons 2.0: We need to move to Location-based Information infrastructure

• Leads to better handover– Leads to a much better use of network

infrastructure– It needs to tell the mobile node about

individual networks• Power of the transmitter, where the access points

are located.

– It also needs to know about the relationships between the individual networks.


Layer 5: End User Transport System

• Specifies how data is routed to individual hosts and transport protocols for error correction, reliability and Quality-of-Service requirements– Encompasses Layer 3 and Layer 4 in the OSI model

• Different approaches– Keep the same protocols as in the core network– Keep TCP/IP, but modify TCP– Don’t modify TCP but try to get it to respond more

quickly to network outages– Try a completely new protocol suite


Layer 5: The case for a new transport Infrastructure

• A new transport system could be more suited for wireless networking

• Do all machines have to have an IP address to use the Internet?

• No.. Look at Network Address Translation (NAT)• Translation is done between a private address and

port to a global address and port at the NAT server


Layer 5: Continued

• A global IP address in the case of NAT is really being used as an endpoint in the core network

• So we can use another network scheme in the peripheral network once we can specify how we map it to TCP/IP or UDP/IP in the core network


Y-Comm’s view of the Future

PERIPHERALWIRELESSNETWORK

CORE NETWORK

PERIPHERALWIRELESSNETWORK

Core EndpointsIn Access Network

QoS, Secure Connection


View corresponds with other ideas

• Faster LAN systems– Optimize DNS, streaming video from local

caches

• Integrate protocol with applications– Tuneable transport– Remove the user/kernel limitations

• Use as a local signalling protocol– Encapsulates TCP packets


Simple Protocol

PK_TYPE Flags CHKSUM

TOTAL_LEN PBLOCK TBLOCK

PRI CB

SYNC_NO WINDOW_SIZE

MESS_SEQ_NO MESS_ACK_NO

DEST_ID SRC_ID


The Simple Protocol• DEST_ID (16) – identifying remote end• SRC_ID (16) – from source end• PK_TYPE (4) - packet type• PRI (2) - supports 4 priority levels• CB (2) – supports ECN• CHKSUM (16) – sixteen bit checksum• TOTAL_LEN (16) – total packet length• PBLOCK (8) – the present block• TBLOCK (8) – the total number of blocks• MESS_SEQ_NO (16) – last message sent• MESS_ACK_NO (16) – last message received• SYNC_NO (8) – the last ACK received• WINDOW_SIZE (24) – the window size


Lesson 3.0: Local support is now essential to the Future

Internet

• Presence of heterogeneous networks

• Support for mobility

• Need for local signalling

• Need for local transports – Don’t need to change TCP

• Need for local knowledge

• Can’t ignore that any more


Heterogeneous Networking and Multi-homing

• Because devices will have several interfaces, there will be multi-homing issues

• Solutions such as Mobile IP which depend on Home and Care-of-Addresses are not scalable

• SCTP helps but works on the transport level only

• Need to look at the network addressing scheme


Does IPv6 help?Look at the IPv6 Address Format


Advantages of IPv6

• Uses a global Interface_ID so it is very easy to construct a new address using auto-configuration– So I don’t need a foreign agent– Since the Interface_ID does not change if I do

a horizontal handover, it is easier for the network infrastructure to work out what is going on

• Does not help with vertical handover


Pressure for Change• Mobile Systems

– Efficient Vertical Handover (Y-Comm)

• Multi-path TCP– Allowing TCP to use all the device interfaces to

transfer data• IETF, Jon Crowcroft, Cambridge

• Pressure to optimize network resources– Switches and routers have limited memory, etc.

• Internet of Things– Networking should be based around devices

themselves not the interfaces they use


Different Approach

• Split the IP address into 2 distinct parts– Node_ID : identifies the device

• Independent of the number of Interfaces the device has

• Given when the device was created; burnt into device;

• Recycled when the device is no longer used

– Location_ID: identifies which network the device is using. A multi-homed device will have several Location_IDs


Proposed IP Address Format

LOCATION_ID NODE_ID

127 063


History behind this• First proposed by LIN Group in Japan (2000-

2001)• Some work done at AT&T Labs on supporting

this paradigm– Mapp and Fraser (2001)

• Led to the development of EUI-64– Evolve the Ethernet Mac Address into a Node_ID

• Current work on ILNP lead by Saleem Bhatti from St Andrews


Why is this good?• Node_ID allows the networking

infrastructure to know that network interfaces are co-located

• Optimize network resources– In the core network we could use the

Node_ID as a general guide to where the device is located. Use the Location_ID to choose which particular local network to use to forward the packet to that device

– Refinement of HMIPv6


Additional Help is needed

• Some observations– It would be good to know that the device is

stationary in a given network• Cache the Location_ID directly in the routing table

– Good for servers as they are stationary

– Reduce the visibility of servers• Need to reduce DDoS attacks

– Support of using different interfaces• Multicast, broadcast, local any-cast, etc.


So we are proposing to modify to address format

LOCATION_ID NODE_ID

0 12763

NODE_IDLOCATION_ID

1270 55 63

NETADMIN


NODE_ID =Global Node Identifier (EUI-64)

0 63

NETADMIN = INFMSF S

0 8

LOCATION_ID = SUBNET

0 55

GLOBAL ROUTING PREFIX

39

NEW STRUCTURES


SF- Scope Field

• Introduced by the Y-Comm Group– Ring-based Security model

• Aimed at protecting servers by reducing access to them

• Servers act within a defined network scope– Only entities within that scope can access the

server– If you are outside the scope, your packet is

blocked by the network infrastructure


Scope Field – 2 bits• 00 - Only processes on the same machine

can use this server• Location_ID must be the loop-back address

• 01 - Only processes on the same LAN can access the server

• Location_ID must be the same LAN as server

• 10 – Only processes on the same Admin Domain can access the server

• Location_ID must be site-address

• 11 – Server is globally accessible


Other bits in the NetAdmin Field

• S – indicates that the device is stationary with regard to a given network – Physically stationary – Servers– Relatively stationary as determined by a

location system

• M – indicates that Node_ID is being used as a multicast address, this allows multicast packets to be sent on network


Interface_IDs can make a comeback

• Interface_IDs banished from the New address format– Means we will have to map the Location_ID to

the Interface_ID before we could send a packet on a given network. Slow performance

• Other observation– Bluetooth and other short range systems do

not need a Location_ID (network) and Interface_ID might be better


Re-Introduce it by indirectlyINF field (4 bits)

• An interface can be uniquely represented within the address format by using an interface number– Controlled by the device.

• Map interface # to MAC address• Give special meaning to certain values

– 0 – any-cast – packet is sent on any available network interface of the mobile device

– 0xF – broadcast packet is sent on all available network interfaces of the mobile device

– 0x1 – called the primary interface


INF • Support for pseudo/virtual interfaces

– Add features such as security • OpenSSL, FreeSwan, provides IPSec services

• Applications can query interfaces on a device– Master locator– Map interfaces #s to Quality-of-Service (QoS)

parameters

• Bluetooth and other point-to-point system could use the INF only and not bother with the Location_ID


Lesson 4.0: Can’t ignore multi-homing any longer

• Crucial for heterogeneous networking

• Need to concentrate on devices and not their interfaces

• Need to think about keeping it flexible and efficient

• Urgent


Layer 6: QoS Layer

• QoS is the most dynamically changing component in heterogeneous networking

• Applications running on heterogeneous devices need support to handle this

• Two Concepts of QoS– Downward QoS– Upward QoS


Layer 6: Downward QoS

• Mainly to support legacy applications

• The application specifies a minimum QoS and the QoS layer does the mapping between the QoS that the application requires and the QoS that is currently available - but is dynamically changing


Layer 6: Upward QoS• For applications that should adapt to

changes in QoS, e.g. Multimedia services, etc– The QoS layer therefore signals the

application using an event mechanism to indicate changes in the available QoS

– Applications can specify routines that will be called when the events occur

• Similar to the X Window System


QoS Layer

APPLICATION LAYER

QOS LAYER

END TRANSPORT LAYER


DOWNWARD QOS

APPLICATION LAYER

QOS LAYER

END TRANSPORT LAYER


UPWARD QOS


Lesson 5.0 Make QoS the real interface to the network

• Applications should not really have to know about TCP or any other protocol

• Replace transport protocols on the fly

• Allow applications to adapt if they can


Last area: Security

• Security is part of Quality-of-Service

• QoSS – specify security as part of QoS– Changes in security are regarded as changes

in the QoS

• Security needs to be on different levels and involves both Core and Peripheral Frameworks

• Allow several layers


The Y-Comm Framework showing its Security Levels- New Security Level

HARDWARE PLATFORM (MOBILE NODE)

HARDWARE PLATFORM (BASE STATION)

NETWORK ABSTRACTION (MOBILE NODE)

NETWORK ABSTRACTION (BASE STATION)

VERTICAL HANDOVER

POLICY MANAGEMENT

END SYSTEM TRANSPORT

QOS LAYER

APPLICATION ENVIRONMENTS

(RE)CONFIGURATION LAYER

NETWORK MANAGEMENT

CORE TRANSPORT

NETWORK QOS LAYER

SERVICE PLATFORM

CORE NETWORKPERIPHERAL NETWORK

SAS

NTS

NAS

QBS


Security in Y-Comm• Network Architecture Security (NAS)

• Security dealing with the deployment and management of different wireless technology

• Managed from the Policy and Management layers

• Network Transport Security (NTS)– Security dealing with end-to-end transport through Y-Comm

• Done at Layer 5, NAT, IPSec, etc

• QoS Based Security (QBS)– Look at QoS Issues

• Looks at SLAs, prevents overloading• Looks at Denial of Service Attacks

• Service and Application Security (SAS)– Security dealing with running applications and

deploying services• AAAC, ACLs, User-based security


Lesson 6: Security needs to consider the effect of an open Architecture

• Security needs to be part of the communications system

• Also needs to be part of QoS

• Security is about protecting entities and not just data– Concept of Security models

• Connection• Ring-based• Vertical Handover


Lesson 7: New business models

• Y-Comm is doomed to failure

• No academic funding – Not about TCP/IP– Not interested in tinkering around the edges

• No industry funding– Y-Comm will destroy the revenue streams of

current mobile providers– They will not put money in unless we show

them how they are going to make money


Any Questions?

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