Implementation of TCP over multiple wireless interfaces

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CS397

• Implementation of TCP over multiple wireless
  interfaces
• Guide Prof. Bhaskaran Raman
• Group Members
• Abhinav Bhatele
• Vikas Kumar

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MOTIVATION
CS397

• Present Scenario
• Multiple wireless technologies
• Mobile clients equipped with different wireless
  interfaces
• Overlap of their coverage areas can be utilized
• Proposed Architecture
• A fixed IP address to connect to the remote
  server
• Network proxy to capture packets for the client
• Use of care-of-IP addresses
• IP-in-IP encapsulation

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DIAGRAM
CS397
Base Station1
Server
Network Proxy
Mobile Host
Base Station2
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MAIN FEATURES
CS397

• Bandwidth Aggregation (BAG)
• Introduces the problem of packet reordering
• PET Algorithm for TCP Applications
• Packet-Pair based Earliest-Delivery-Path-First
  Transmission algorithm
• Minimizes packet reordering
• Buffer Management Policy (BMP) on client side
• Has to be used since some amount of reordering is
  inevitable
• Remaining Problem Loss Isolation

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PROBLEM STATEMENT
CS397

• LOSS ISOLATION
• Different paths have different loss rates
• Loss on one path should not affect the possible
  throughput on other paths
• To propose a solution
• To study the performance of the proposed approach
  under a variety of network conditions

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PREVIOUS WORK
CS397

• BAG-TCP.pdf
• Paper by Kameswari Chebrolu, Bhaskaran Raman and
  Ramesh Rao talks about BAG, PET and BMP
• Details about the Architecture, Services,
  Experimental Methodology and Design Criteria
• CS625 Course Project
• By Rupesh R. Mehta, Niraj N. Kalamkar and Rohan
  R. Shetty
• Implementation of Multiple TCP connections using
  socket programming

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SOLUTION
CS397

• The proposed solution is termed as TCPinTCP
• Strip off the ethernet header
• Add TCP and IP header over the packet
• Send these packets on different TCP connections

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SOLUTION DETAILS
CS397

• The various tasks
• Introducing bandwidth restrictions
• Scheduling the packets on different connections
• Introduction of cross-traffic
• Introduction of random wireless errors
• Comparative study with ideal case (MTCP)
• Implementation Details
• 2 TCP connections between HA and DN
• N cross traffic connections between Server and DN
• Route packets from Server for DN and MH through
  HA

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DIAGRAM
CS397
Server (csews111)
Home Agent (csews109)
Mobile Host (csews104)
Dummy Node (csews108)
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RESULTS
CS397
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RESULTS (contd.)
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CONCLUSIONS
CS397

• Factors affecting Bandwidth
• Bandwidth of TCP connections throughput
  increases with increasing bandwidth
• No. of cross traffic connections decrease the
  total throughput
• Wireless errors decrease the throughput
• Bandwidth Split increasing difference in
  bandwidth decreases the effective throughput

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Questions !!!!!!!
CS397