Some main trends in networking and
related open problems
Prof. Daniel Kofman
ENST-Telecom Paris
Daniel.Kofman@enst.fr
TAU, Israel, 2004
Content
 General
context
 Core area networks
 Fix and mobile access, and sensor networks
 Traffic engineering
 Euro-NGI presentation
 Open discussions
Internet, historical perspective

First generation, before 1992
Research network
 Telnet, Email, File Transfer
 Low traffic, low number of users


Second generation , the ’90s
Commercial services, ISPs
 Web and basic peer-to-peer
 Traffic and number of networks explosion
 Mainly Best Effort approach and simple engineering rules



Main issue: capacity (network and addressing)
Third generation, from now on

Services evolution and convergence

Triple play (Internet/Telecom/Media convergence)
Network and services ubiquity, ambient intelligence
 New networking architectures are required
 New engineering rules are necessary

Towards IP Multiservice Networks
P2P
Grid
Triple
play
Web
VoIP
MmediaoIP
Support of all
services over IP
SERVICES
IP
INFRASTRUCTURE
IP covers the
Technology
diversity
A new organization of the chain of value
Contenu
Packaging
Accès
Transport
Gestion
Terminaux
client
… from
d'uneacompétition
competitionorganisée
organizedpar
perservice
service
sur l'ensemble
over
the whole de
chain
la chaîne
value ...
de valeur ...
Services
Production de
contenus
Production de
contenus
Production de
professionnels
Services domicile
Distribution
E - Médiation
Agrégation
A/A&S
Portail
Agrégation
de contenus
Portail
Services
traditionnelle
E - Médiation
de l'offre
Marketing
A/A&S
de l'offre
de contenus
Agregation
Agrégation
Accès
Transport
Transport
IAP
Accès
Access
Transmission BL
Gestion
de
de
de
l'infrastructure
raccordement abonné
Commutation BL
services
Agrégation
Agrégation
de contenus
Gestion
Client
de contenus
Services mobiles
ServicesMarketing
mobiles
de services
of
services
Bureau
professionnels
Services domicile
client
Management
Home
Area
Network
Mobiles
Terminals
Terminaux
Production de
services
… à un schéma
…towards
a competition
concurrentiel
scheme
organisé
organized
par segment
per activity
d'activité
segment
Source: CSTI
Any service, any time, everywhere
Create New Service
OK
Offered Services
IP centrex
Dist. office
Network Operator
Contracted
Services
Modify Service
Backbone
Customer
Access Network
Customer
Premises
Examples of Internet evolutions









From a data network towards a multiservice-multimedia network
From unicast to multicast
The usage of new lower layer technologies (IP/ATM, IP/SONET,
IP/DWDM, etc.)
From legacy dial-up to ADSL, HFC, WLL, Wi-Fi, FTTx, PLC, satellites,
etc.
From fix to mobile network
From isolation towards service integration with, for example, the
telephony network: NGN architectures
Towards the provisioning of telecommunication services for private
companies: IP VPNs
From software based to hardware based routers architectures (Giga/Tera
routers, flow based routers, etc.)
A very fast evolution of the structure of the traffic requiring new traffic
engineering approaches
The Backbone Evolution, Global View
Different Approaches to Increase
Backbone Capacity
Overlay Networks
R3
R1
R2
IP
C3
C2
C1
C4
ATM
SDH
WDM
Increasing Capacity for IP transport,
Option I: IP over ATM
R
R
R
IP
Customer
Premises
ATM
SDH
Increasing Capacity for IP transport,
Option II: IP over SONET (SDH)
R
R
R
IP
Customer
Premises
SDH
Increasing Capacity for IP transport,
Option III: MPLS
LSR
LSR
LSR
MPLS
SDH
oher
Customer
Premises
LSR
LSR
Switching Capacity, not an issue any
more, but MPLS still needed
LSR
LSR
LSR
MPLS
SDH
(??)
Customer
Premises
• Quality of Service
• Evolved VPN
• Traffic Engineering, Protection
• Multicast
Overlay Networks
R3
R1
R2
IP
C3
C2
C1
C4
ATM
SDH
WDM
Main trends
R3
R1
R2
IP
C3
C2
C1
SDH
C4
ATM
Rapid and Predictable Restoration
Standard Time Division Multiplexing
LSR
IP and ATM integration
Label Swapping Paradigm
G-MPLS
SONET/SDH
Dynamic Allocation and Control?
MPLS
10Gbps
10Gbps
10Gbps
10Gbps
10Gbps
Increasing
Capacity Requirements
10Gbps
OCX
OCX
DWDM
Dynamic Allocation and Control?
Some Interesting problems
 Multi-layer
dynamic routing
 Multi-layer protection/restoration
 Layout optimization under variable traffic
 Control and Scheduling in OPS/OBS
From IP over ATM …
IP
ATM
… Towards MPLS over OTN
MPLS
OTN
Required granularity change
The Overlay model


Layers are independent in term of Routing
For instance:


IP routers don’t see physical topology
Physical channels are (semi-)permanent (Static Overlay) or switched
(Dynamic Overlay).
P
T
The Peer model

Equipments of both layers are “peers” w.r.t.
routing and signaling.


Routers “see” physical topology and can open ondemand channels by signaling.
In this example, optical switches don’t necessarily “see”
IP topology but transport IP routing information as IP
opaque information.
Interesting problems
 Multi-layer
dynamic routing
 Multi-layer protection/restoration
 Layout optimization under variable traffic
 Control and Scheduling in OPS/OBS
 Extension of G-MPLS for multipoint to
multipoint connections
Grooming strategies and
Statistical multiplexing modeling issues
Narrowband access, high aggregation



Broadband access, low aggregation
Realistic costs functions lead to MINLP problems
Given the increase in broadband network access, core
network flows are sporadic and network flows do not
simply add
Hence, need for new statistical models and related
grooming strategies
From LAN ATM towards MAN/WAN
Ethernet

First attempt of technology convergence, pushing ATM from the WAN to the
LAN




Second attempt of technology convergence, pushing Ethernet from LAN to
Access, MAN and WAN
What about the AN and the MAN ?










In order to face the increasing requirements of LANs, ATM was introduced based in the
LANE architecture standardized in 1995 by the ATM Forum
But ATM lost the terminal battle and then, partially as a consequence, the LAN war.
From SDH to NG-SDH
From A-PON to E-PON
Ethernet rings and RPR
ATM based xDSL architectures and
Ethernet based xDSL architectures
UMTS, from R99 ATM towards R5 and beyond: all IP
Ethernet over Metro WDM
Etc.
Requirement for a control plane: G-MPLS, L2LSPs and FA-MAs
Requirement for new equipment architectures
Generic / Hybrid Switches
Design of the switching fabric scheduler
Capacity optimization vs QoS guarantees
IP Transport Overview: Overlay
Networks
Applications
IP
Ethernet
ATM
SDH
WDM
The Access Network
Technologies for the Access Network
Access Networks Evolution
Context

New technologies and regulatory conditions
 xDSL and
Unbundling of the local loop
 HFC-Hybrid Fiber Coax
 802.11 and WiFi, 802.16 and WiMax
 Satellites (LEO/MEO/GEO)
 3rd Generation and beyond Mobile Systems
 Power Line Communication (PLC)
 FTTx, PON, Metro WDM
 Next Generation SDH rings
 Ethernet rings
Historical non competing operators would like to
compete on every service on every market.
 Main issue: multi-technology integration

3G and beyond Mobile Networks

Cell capacity optimization and fairness in
HDR/HSDPA networks
 Back
to TDMA
 Considering traffic evolution increases the capacity of the cells
 Admission control and scheduling

Opportunistic policies
Transport protocols for wireless and mobile networks
 Horizontal integration, All IP mobility

 Ubiquity,
vertical handover and roaming
Network Architecture Evolution,
Technology Integration, Network Control
 Horizontal
integration
 From extremely small to immensely big
 Sensor networks, PAN, Ad-hoc networks, access to
infrastructure networks
– The IP networking model is no longer applicable

Ubiquity, Mobility, Context Awareness, Location Based Services
 Vertical roaming
 Seamless interworking and handover, transparent and dynamic
adaptation of the used technology
 End
to End services availability in a Multi-domain
context
Network Architecture Evolution,
Technology Integration, Network Control
 Vertical
Integration
 Multi-layer
networks
 Unified control and management planes

Multi-layer routing, protection, restoration, etc.
 Integrated
design of physical, MAC, routing and
upper layers including innovative air interfaces,
optical packet/burst switching, etc.
 Services Overlays


Service planes and related middlewares
P2P, Grids, others
Sensor Networks
 Deployment
optimization
 Coverage,
connectivity and lifetime optimization
 Heterogeneous sensor networks
 Integrated
 Coverage
 Enhancing
level 2 and level 3 design
under routing constraints
used models by including physical
and MAC layers constraints
Services overlays
 Optimal
and fair resources allocation in P2P
systems
 Optimal inter-working between P2P and CDN
systems
Traffic Engineering for IP
networks
Traffic Engineering : Introduction

Various time scales

Physical Resources Planning
Layouts and virtual topologies design
 Load sharing
 Routing (e.g. QoS sensitive routing)

Admission control
 Flow and congestion control
 Scheduling and buffer management


Resource Oriented Vs. Traffic Oriented
Trend: Flow aware networking (FAN)






The traffic evolution at the various time scales became very
difficult to predict
Thus, there is a requirement for measurement based traffic
engineering approaches
Different approaches has to be applied to different families of
traffic but the classification has to remain simple
 Streaming, elastic long, elastic short
DiffServ requires a complicated traffic engineering to be
efficient
Intserv do not scale
Requirement for other approaches: Flow aware Networking
Flow aware networking and cross-protect
Traffic Engineering : Introduction

Various time scales

Physical Resources Planning
Layouts and virtual topologies design
 Load sharing
 Routing (e.g. QoS sensitive routing)

Admission control
 Flow and congestion control
 Scheduling and buffer management


Resource Oriented Vs. Traffic Oriented
Content
 General
context
 Core area networks
 Fix and mobile access, ad-hoc and sensor
networks
 Traffic engineering
 Euro-NGI presentation
 Open discussions
Euro-NGI
 57
institutions, 173 researchers, more than 300
PhD students, 18 countries
 Academy
and industry
 See www.eurongi.org for the list
 Leader: GET-Telecom Paris
 European
Commission Contribution:
5 000 000 Euros (10% of the total budget)
 For
the first 3 years
 Starting
Date: December 1st, 2003
Organization of Research Activities

Joint Research Activities: 6
JRA and 25 WPs for which



 Specific workshops
 Advanced tools for
communication and sharing of
information
 Management Committees in
charge of controlling that
integration is achieved
Architectural Domains
Core
Fixed
Access
Mobile
IP
Services
Access Networking Overlays
Network Architecture Evolution, Technology Integration,
Control, Managing the diversity
Traffic Engineering, Traffic Management, Congestion
Control and End to End QoS
Optimisation of Protected Multi
-Layer Next Generation
Networks: Topology, Layout, Flow and Capacity Design
Experimentation and Validation Through Platforms
Modeling, Quantitative Methods and Measurements
Socio-Economic Aspects of the Next Generation Internet
Research Domains

Integration and
rationalization of research
efforts
Large working groups have
been created
Workshops have been
scheduled
The field for cross fertilization
between activities and
workpackages has been
prepared
Technology explosion, examples
Core Networks and MAN: Optical Packet/Burst/Flow
Switching, WDM, NG-SDH, Ethernet, IP over OBS, ...
 Wired Access Networks: xDSL, HFC, FTTx, PONs,
Metro-DWDM, PLC,
 WL / Mobile Networks: WLL,, Wi-Fi, Wi-Max, AdHoc, Sensor, Satellite (constellations), GSM/GPRS,
UMTS, 4G, etc.
 Network protocols and architectures: IPv6, Mobile IP,
Cellular IP, Transport protocols (TCP optimization
for mobile channels, etc.), MPLS, G-MPLS, etc.
 Services infrastructures: Services overlays, Peer-topeer, Grid, IP telephony/multimedia, LBS/CBS,
Midlewares, etc.

JRA.1 Network Architecture Evolution,
Technology Integration, Network Control
 Horizontal
integration
 From extremely small to immensely big
 Sensor networks, PAN, Ad-hoc networks, access to
infrastructure networks
– The IP networking model is no longer applicable

Ubiquity, Mobility, Context Awareness, Location Based Services
 Vertical roaming
 Seamless interworking, transparent and dynamic adaptation of
the used technology
 End
to End services availability in a Multi-domain
context
JRA.1 Network Architecture Evolution,
Technology Integration, Network Control
 Vertical
Integration
 Multi-layer
networks
 Unified control and management planes

Multi-layer routing, protection, restoration, etc.
 Integrated
design of physical, MAC and upper layers
including innovative air interfaces, optical
packet/burst switching, etc.
 Services Overlays


Service planes and related middlewares
P2P, Grids, others
JRA.2 Traffic Engineering, Traffic Management,
Congestion Control and End to end QoS

Mechanisms and protocols for controlled bandwidth sharing






Traffic management in a multi-provider context


Admission control, Implicit admission control, resources allocation,
services differentiation, QoS and pricing, etc.
Traffic engineering for a cost effective network


Evolution of Congestion Control protocols, beyond TCP
Interaction with MAC layers (e.g. in wireless networks)
Control algorithms in networks with variable-capacity links.
Active queue management
Per-flow aware networks
Routing in multilayer networks, constrain based routing, load sharing,
layout optimization, etc.
QoS in multi-service wireless networks


Application of techniques for congestion control, traffic management
and traffic engineering to the specific context of multiservice wireless
networks: CDMA, WLAN (802.11x), WiMax, ad hoc and sensor
networks.
Planning of new generation celular networks and of hybrid wireless
access networks
JRA.3 Optimisation of Robust Multi-Layer NGIs:
Topology, Layout, Protection, Flow and Capacity Design
 Optimisation
of protected multi-layer core
networks: topology, layout, flow and capacity
design
 Optimisation of protected access networks
topology, layout, flow and capacity design
 Study of methods for achieving network
resilience/robustness
 Development of a European Network Design
Tool for Next Generation Internet
JRA.4 Experimentation and Validation
Through Platforms

Integration and sharing of Platforms
 Experimental
European wide IP over WDM, MPLS,
IPv6 network deployment
 Evaluation of innovative services: Grids, virtual
reality based CAD, Telemedecine, etc.
 Software-based
Test-Beds Development for
Traffic Engineering Experimentation
 Distributed
 European
emulation of next generation networks
wide Measurement Platforms
JRA.5 Modelling, Quantitative Methods
and Measurements
 IP traffic
characterization, measurements and
statistical methods
 Dynamics of networks under new traffic
paradigms
 Spatial network modelling and stochastic
geometry
 Networks optimization and control
 Numerical and analytic methodologies
JRA.6 Socio-Economic Aspects
 Quality
of Service from the users perspective
and feed-back mechanisms for quality
control
 Payment and cost models for Next Generation
Internet
 Security Spreading of excellence
Content
 General
context
 Core area networks
 Fix and mobile access, ad-hoc and sensor
networks
 Traffic engineering
 Services overlays
 Euro-NGI presentation
 Open discussions