UnicastMulticast Bridging for CDEEP EDUSAT Satellite Network MTP
Unicast-Multicast Bridging for CDEEP EDUSAT Satellite Network MTP Final Presentation Guided by, Prof. Purushottam Kulkarni Prof. Sridhar Iyer Presented by, Mohammed Nazeem V 08305038 MTech 2, CSE
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 KRe. SIT • Only one Hall to conduct lectures
CDEEP Setup Has four Video Recording Labs Seminar Hall KRe. SIT EEG 401 Video Lab (Math building) A 1/A 2 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 KRe. SIT (CDEEP Network Setup in KRe. SIT
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 Unicast only Network Connected to multicast backbone Similar to Lecture Hall Similar to IIT-network Seminar Hall KRe. SIT Similar to EDUSAT Network cloud Network setup for Mbone webcase at IFSA Conference site [reference: MBone Webcast: Network Setup and Data Collection, Milan Nikolic , Dan Hoffman , Ljiljana Trajkovic, 2003]
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 and tunneling Network layer Gateway with tunneling Tunneling at routers
Extending the EDUSAT network Nothing much to be done, can be done if no other solution may be found Additional Infrastructure, does not meet the goal of using existing IIT-B network Extending EDUSAT network
Extending the audio/video cables Additional infrastructure for laying down these cables Cables have a limit on range 10 -20 metres Extending Audio/Video cable
Application Layer Gateway Video Server application of ISRO removed What about the Teacher's terminal? Application Layer gateway
Transmitting RAW audio/video over network Same Video Server Application used What about Teacher's terminal? Transmitting RAW audio/video over the network
Network Layer gateway with NAT 192. 168. 0. 11 192. 168. 0. 12 10. 254. 75. 2 Gateway at network layer doing NAT 192. 168. 0. 1
Network Layer gateway with NAT Video server and Teacher's terminal out of the EDUSAT network EDUSAT Running same ISRO Applications Gateway at network layer doing NAT
Network Layer gateway with NAT and tunneling 192. 168. 0. 1 10. 129. 154. 205 10. 105. 11. 203 10. 254. 75. 2 192. 168. 0. 10 192. 168. 0. 11 10. 105. 1. 250 NAT with tunneling 10. 129. 1. 250
Network Layer gateway with NAT and tunneling Anywhere inside the campus, same video server and Teacher's terminal Tunneling between EDUSAT network and IIT-B network Multicast Packets being encapsulated inside unicast IP packets No additional infrastructure NAT with tunneling
Network Layer Gateway with tunneling Extended EDUSAT network Interconnected EDUSAT Satellite network
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 - Fabula. Tech 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 gateway The transmission did not reach the student's terminal Transmitting RAW audio/video over network Did not work for video capturing devices Network Layer gateway with NAT Worked for local LAN without a gateway Network Layer gateway with NAT and tunneling Tunneling worked, packets get dropped at routers for GRE tunnel Network Layer Gateway with tunneling Worked with openvpn using bridging
Tunnel performance experiment Without tunnel Bridging With tunnel With Cipher
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 KRe. SIT 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 Qing. Ji, Lu Jian , Beijing University of Aeronautics & Astronautics , 2001 [3] E. Amir, S. Mc. Canne, 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 , Haakon Bryhni, and Steinar Sørlie. Unicast extensions to IP multicast. In Proceedings of the Protocols for Multimedia Systems PROMS’ 2000, pages 60– 69, Krak w, Poland, 2000. ISBN 83 -88309 -05 -6.
Demo
NAT in action From machine connected to NAT To public network From public network To machine connected to NAT tcpdump output of private network machine
NAT in action To public Network From NAT machine From public network tcpdump output of NAT machine To NAT machine
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