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 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
Unicast only
Network
Connected to
multicast backbone
Similar to
Lecture Hall
Similar to IIT-network
Seminar Hall KReSIT
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

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 - 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 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 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 ,́ 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