ADSL

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ADSL
IP-Multicast
over

• Brigitta Lange
• NEC Europe Ltd.
• CC Research Laboratories
• Adenauerplatz 6
• D-69115 Heidelberg
• lange_at_ccrle.nec.de

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Overview

• Internet Application Trends
• Experiences ADSL Pilot Aachen
• Requirements for Multicast Support
• Multicast Architectures for ADSL
• Multicast Gateway
• Multicast over PVC
• Performance Results
• Field Trial Homelearning over ADSL
• Summary

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Internet Trends (1)
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Internet Trends (2)
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Internet Trends (3)
Point to Point
Point to Multi-Point Multi-Point to Multi-Point
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ADSL Pilot Aachen (1)

• ADSL Pilot Aachen
• Cooperation RWTH Aachen, DTAG, NEC
• launched in February 1998
• currently 700 residential users
• Objectives
• Test/ Evaluation ADSL Technology
• High speed Internet/ remote LAN access
• Analysis of User Behavior

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ADSL Pilot Aachen (2)

• Experiences user behavior
• ADSL encourages multimedia applications
• enables high-quality tele-working
• growing demand for multimedia collaborative
  applications
• audio/video conferencing, distributed games
• Delimiter for multimedia group applications
• require efficient PMP communication
• lack of IP-Multicast support in access network
  

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Introduction to IP-Multicasting
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Broadband Access Networks

• Roll out of ADSL
• bandwidth no longer delimiter
• delivery of broadband services to the homes
• Success of ADSL networks
• depends on high bandwidth applications
• Network infrastructure has to support emerging
  services
• Multicast is essential for these applications
• IP-Multicast support is a key requirement for
  broadband access networks

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ADSL Network Architecture
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ADSL Network Scenarios

• PPP over ATM over ADSL
• PPP provides Authentication Accounting, Address
  assignment
• ATM provides QoS guarantee
• Connection between End-user and NSP
• by ATM PVCs or by ATM SVCs
• In near future only PVCs will be available
• Goal Provide IP-Multicast in this scenario
• short-term solution based on PVCs

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Requirements for IP-Multicast Support over
ATM/ADSL

• Key aspects
• scalability ( of clients, of groups)
• efficiency of data replication
• avoid broadcasting all multicast groups
• support for dynamic joining and leaving
• accounting facilities
• Additional aspects
• QoS
• implementation effort
• smooth PVC -gt SVC migration

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Multicast Architectures for ADSL

• Multicast Gateway (short-term solution)
• Multicast client-server application
• access through Unicast tunnels
• Multicast over PVC (mid-term solution)
• based on MARS/MCS
• Multicast in PVC based access networks
• MARS/MCS (long-term solution)
• IETF proposed standard
• good scalability, based on SVCs

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Multicast Gateway (1)

• Architecture

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Multicast Gateway (2)

• Performance Measurements

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Multicast Gateway (3)

• Advantages
• immediate realization
• easy implementation
• Disadvantages
• no real multicast ADSL client has to install
  special software
• inefficient replication of packets at
  application layer (end user space)
• not scalable with number of clients

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Multicast over PVC (1)

• Adress resolution MARS
• Replication/Forwarding MCS
• Two approaches for data forwarding
• Multiple PP PVCs from MCS to each host
• selective sending to hosts joined
• replication done at the network level (kernel)
• PMP PVC to all hosts of cluster
• broadcast to all hosts, non-selective
• efficient replication done at the ATM level
• flooding of users accesses with useless traffic

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Multicast over PVC (2)
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Performance Comparison

• Bandwidth supported without losses for the
  different Multicast Architectures

• Result Multicast over PVC more efficient
• supports larger number of end users

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DFN Project ANETTE

• ANETTE Applications and NEtwork Technology for
  Teleteaching
• joint proposal of the universities of Mannheim,
  Freiburg, Aachen and NEC
• funded by DFN (Germ. Research Network)
• project duration June 1999 - May 2001
• ATM/ADSL Field Trial for advanced Homelearning
  and Teleteaching scenarios
• Testbed for the proposed Multicast Architectures,
  scalability studies

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ANETTE Scenario
Home Students Aachen
ADSL
B-WIN DFN
Lecture Hall Universities
Home Students Mannheim
ISDN
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ANETTE ADSL Trial Aachen
StudentsHome
CO
Central Office
RWTH Aachen
1
UniversityBackbone
ATM Backboneof B-Win
ATU
1

ONU
ONU
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MCRouter
1
ATMXSwitch
2
ADSL Multicast Access Server
ATU

ONU
ONU
ADSL Multicast Access Server
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1

3?
ONU
ONU
ATU
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Uni Mannheim,...
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ANETTE Teleteaching Tools
Video
Whiteboard Import
Whiteboard
Audio Control
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Summary

• Growing demand for multimedia group applications
  based on point-to-multipoint communication
• IP-Multicast support in RBB networks needed
• Two step proposal for ATM/ADSL networks
• Multicast Gateway (short term)
• Multicast over PVC (mid-term, more efficient)
• Evaluation of both architectures in ADSL field
  trial for Interactive Homelearning scenarios