Notes - MIECT
Redes E Sistemas Autónomos
Notes - MIECT
Redes E Sistemas Autónomos
  • Redes e Sistemas Autónomos
  • Peer-to-Peer Systems and Networks
    • Content Distribution Networks
    • Peer-to-peer networks
      • Types
    • Structured vs Unstructured
    • Fully Decentralized Information System
    • FastTrack/KaZaA
    • OpenNAP/Napster
    • BitTorrent
  • InterPlanetary File System (IPFS)
    • IPFS
      • Bitswap
    • Connecting an IPFS node to the P2P network
    • Searching in DHTs (Structured)
    • File Search
    • Security
  • Ad-Hoc Networks
    • Mobile Ad-hoc networks
    • Application Scenarios
    • Routing
      • AODV - Ad Hoc On-Demand Distance Vector Routing
      • OLSR - Optimized Link State Routing Protocol
      • LAR – Location Aided Routing
      • Batman
    • IP Address Assignment
  • Self-organized systems: Data, learning and decisions
    • Use Cases and Data
    • Machine Learning
      • Supervised Learning
      • Neural Networks
      • Reinforcement Learning
      • Unsupervised Learning: K-means
    • Learning
  • Vehicular Networks
    • Vehicular Ad Hoc Networks
    • How do they work?
    • SPAT: Signal Phase And Timing
    • MAP: MAP
    • Manoeuvre Coordination Message (MCM)
    • Communication Technologies
  • QoS and Security
    • TCP- and UDP-based applications
      • TCP-Cubic
    • QUIC
    • TCP-Vegas
    • Classification of Transport protocols
    • Exploiting Buffering Capabilities
    • QoS in UDP: trade-offs
    • Transmission Quality (Batman v.3)
    • QoS-OLSR
    • Security
      • Key Management
      • RSA (Rivest-Shamir-Adleman) Key
      • Key Management in ad-hoc networks
      • Self-organized public key management (SOPKM)
      • Self-securing ad-hoc wireless networks (SSAWN)
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  • Calculation
  • Content ID
  • Examples
  1. InterPlanetary File System (IPFS)
  2. IPFS

Bitswap

PreviousIPFSNextConnecting an IPFS node to the P2P network

Last updated 2 years ago

Calculation

Debt ratio r.

Probability of sending to a debtor.

  • Function drops off quickly as the nodes’ debt ratio surpasses twice the established credit.

BitSwap nodes keep ledgers accounting for the transfers with other nodes.

  • When activating a connection, BitSwap nodes exchange their ledger information. If it does not match exactly, the ledger is reinitialized from scratch, losing the accrued credit or debt.

Sketch of the lifetime of a peer connection:

  1. Open: peers send ledgers until they agree.

  2. Sending: peers exchange want_lists and blocks.

  3. Close: peers deactivate a connection.

  4. Ignored: (special) a peer is ignored (for the duration of a timeout) if a node’s strategy avoids sending.

Content ID

In IFPS, every file or directory has a CID.

  • A unique SHA256 hash is used to identify the file.

Whenever the content changes, the CID also changes.

To keep track of files after being altered, IPFS uses the InterPlanetary Name System (IPNS) where the name is the hash of a public key, stored in the DHT, pointing to the CID of the latest version.

Examples

When a peer wants a block, it broadcasts a Want to all connected peers.

If there is no response, it asks the DHT who has the root CID. Peers who respond are added to the session and subsequent requests are sent only to peers in the session.