unicast-multicast bridging for cdeep edusat satellite network guided by,presented by, prof....
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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