Unicast-Multicast Bridging for CDEEP EDUSAT Satellite Network

Guided by, Presented by,

Prof. Purushottam Kulkarni Mohammed Nazeem VProf. Sridhar Iyer 08305038

MTech 2, CSE

MTP Final Presentation

Introduction

• CDEEP Centre for Distance Engineering Education programme

• EDUSAT Link for live interactive transmission through the satellite

• 125 remote centers across the country

• 2 Mbps uplink and 1 Mbps down link

• Live and interactive teaching

• EDUSAT satellite network of ISRO is multicast.

• Courses transmitted from Seminar Hall KReSIT

• Only one Hall to conduct lectures

CDEEP Setup

Has four Video Recording Labs Seminar Hall KReSIT EEG 401 Video Lab (Math building) A1/A2 Hall (Math building)

All have only webcast transmission except the Seminar Hall – has EDUSAT satellite transmission

Terminals types

Three type of terminals

• Video Server– Transmits the live feed to multicast server

• Student's Terminal (Remote Centre)– Receives the course transmitted– Transmits live feed from the students

• Teacher's terminal– Receives live feed from the students– Monitors the remote centres

CDEEP EDUSAT Satellite Network setup

CDEEP network using Edusat Satellite

CDEEP Network Setup KReSIT

(CDEEP Network Setup in KReSIT

Problem Definition

Study and understand the functioning of CDEEP satellite network

Interconnect EDUSAT satellite network and IIT-B campus network so that courses conducted anywhere in campus be transmitted via satellite.

Main concern is – EDUSAT satellite has Multicast backbone BUT campus network is unicast

Measurement study of CDEEP satellite network and generate quantitative results.

What is to be done ?

Related Work

Network setup for Mbone webcase at IFSA Conference site[reference: MBone Webcast: Network Setup and Data Collection, Milan Nikolic , Dan Hoffman , Ljiljana Trajkovic, 2003]

Connected tomulticast backbone

Similar to EDUSATNetwork cloud

Similar to Lecture Hall

Similar to IIT-networkSeminar Hall KReSIT

Unicast only Network

Proposal of solutions Extending the EDUSAT network

Extending the audio/video cables

Application Layer gateway

Transmitting RAW audio/video over network

Network Layer gateway with NAT

Network Layer gateway with NAT and tunneling

Network layer Gateway with tunneling

Tunneling at routers

Extending the EDUSAT network

Extending EDUSAT network

Additional Infrastructure, does not meet the goal of

using existing IIT-B network

Nothing much to be done, can be done if no other solution may be found

Extending the audio/video cables

Extending Audio/Video cable

Additional infrastructure for laying down these cables

Cables have a limit on range10-20 metres

Application Layer Gateway

Application Layer gateway

Video Server application of ISRO removed

What about the Teacher's terminal?

Transmitting RAW audio/video over network

Transmitting RAW audio/video over the network

What about Teacher's terminal?

Same Video ServerApplication used

Gateway at network layer doing NAT

192.168.0.11 192.168.0.12

192.168.0.110.254.75.2

Network Layer gateway with NAT

Network Layer gateway with NAT

Gateway at network layer doing NAT

EDUSAT

Video server and Teacher's terminal out

of the EDUSAT network

Running same ISRO Applications

Network Layer gateway with NAT and tunneling

NAT with tunneling

10.105.1.250 10.129.1.250

10.254.75.2

10.129.154.20510.105.11.203192.168.0.1

192.168.0.10 192.168.0.11

NAT with tunneling

No additional infrastructure

Multicast Packets being encapsulated inside unicast IP packets

Tunneling between EDUSAT network and IIT-B network

Network Layer gateway with NAT and tunneling

Anywhere inside the campus, same video server and Teacher's terminal

Network Layer Gateway with tunneling

Extended EDUSAT network

EDUSAT Satellite network

Interconnected

Implementation Application Layer gateway

Java Media Framework (JMF) was used to transmit audio and video to multicast server

Transmitting RAW audio/video over network Used a software - FabulaTech USB over Network Version 4.2. I

Network Layer gateway with NAT Used ip tables in linux

Network Layer gateway with NAT and tunneling Implemented tunnel using GRE (Generic Routing Encapsulation) developed by CISCO

Network Layer gateway with tunneling Used openvpn

Observations

Application Layer gatewayThe transmission did not reach the student's terminal

Transmitting RAW audio/video over networkDid not work for video capturing devices

Network Layer gateway with NATWorked for local LAN without a gateway

Network Layer gateway with NAT and tunnelingTunneling worked, packets get dropped at routers for GRE tunnel

Network Layer Gateway with tunnelingWorked with openvpn using bridging

Tunnel performance experiment

Without tunnel

Bridging

With Cipher

With tunnel

Results – Tunnel performance

Slight increase in ping delay as you move right

Day long experiment results

The variation in the jitter and ping delay is very small

Application for automating tunnel setup customized for CDEEP

Java application using swing

Same application for both gateways– One as server– Other as client

Gets network interfaces available• From list choose EDUSAT interface

If client, mention the IP address of other gateway

Challenges faced

Fetching network details of CEEP EDUSAT

Understanding the Problem

Finding out when the CDEEP EDUSAT network was idle

Encoding problem with Application Layer Gateway

Sharing Streaming devices over network

Port misconfiguration while testing NAT on satellite network

Packets getting dropped at routers

Routing problem of multicast through tunnel

Multicast routing daemon had problems

Moving Teacher's terminal and Video server from KReSIT

Synchronization of bridging and tunneling

Conclusions and Future work Conclusions

• We have discussed various possible ways of trying out to find a very appropriate solution.

• The most promising solution would be to implement at the network layer.

• Tunneling is required to transfer multicast packets through a unicast network.

• This technique requires no additional hardwares and is very cheap.

Future Work• Find out whether the solution is scalable as the number of users

receiving as well as the number of servers will increase.

• If performance degrades, improvements in the design of the tunnel itself will have to be made.

References[1] Milan Nikoli, Dan Hoffman, and Ljiljana Trajkovi. Mbone webcast:. August 21

2003.

[2] Multimedia Multicast Gateway Infrastructure , Jin Tian, Chen QingJi, Lu Jian , Beijing University of Aeronautics & Astronautics , 2001

[3] E. Amir, S. McCanne, and H. Zhang. An application level video gateway. In The

Third ACM International Multimedia Conference and Exhibition (MULTIMEDIA ’95), pages 255–266, New Yprk, November 1996. ACM Press.

[4] Peter Parnes, Kre Synnes, and Dick Schefstrm. Lightweight application level multicast tunneling using mtunnel. Computer Communication, 21:1295–1301, 1998.

[5] Tarik Ciˇi L, Haakon Bryhni, and Steinar Sørlie. Unicast extensions to IP multicast. In Proceedings of the Protocols for Multimedia Systems PROMS’2000, pages 60–69, Krak Lw, Poland, 2000. ISBN 83-88309-05-6.

Demo

NAT in action

tcpdump output of private network machine

From machine connected to NAT To public network

From public networkTo machine

connected to NAT

NAT in action

tcpdump output of NAT machine

From NAT machine To public Network

From public network To NAT machine