Chapter 2: P2P Architecture

"Hongik Ingan: Distributed networks empower everyone to be their own host."

2.1 Personal Web Server

Your PC as Server
=================

Traditional server:
  - Runs 24/7 in data center
  - Expensive hardware
  - Managed by company
  - You pay rent

WIA-HOME server:
  - Runs on your PC/laptop
  - Uses minimal resources
  - You control everything
  - Zero cost


Server Components
=================

1. HTTP Server
   - Serves web pages
   - Handles requests
   - Optimized for low resources

2. P2P Node
   - Connects to mesh network
   - Handles NAT traversal
   - Enables discovery

3. Content Manager
   - Stores your pages
   - Manages media
   - Handles caching

4. Security Layer
   - TLS encryption
   - DDoS protection
   - Firewall


Resource Usage
==============

Minimum requirements:
  CPU:     5-10% when active
  Memory:  128-256 MB
  Storage: 100 MB + your content
  Network: 1 Mbps upload

Your old laptop can do this!


Sleep Mode
==========

When no visitors:
  - Server enters sleep mode
  - Uses almost no resources
  - Wakes on incoming request
  - Seamless for visitors

Energy efficient hosting.

2.2 P2P Mesh Network

Network Topology
================

      [Peer A]--------[Peer B]
        /  \            /  \
       /    \          /    \
      /      \        /      \
 [Peer C]----[Your PC]----[Peer D]
      \      /        \      /
       \    /          \    /
        \  /            \  /
      [Peer E]--------[Peer F]
              \      /
               \    /
             [Relay Node]


No Central Server
=================

Traditional:
  All traffic -> Central server -> Users
  Server down = Website down

WIA-HOME:
  Traffic distributed across network
  Your PC down = Cached content served
  Network resilient


Peer Discovery
==============

1. Bootstrap
   - Connect to known peers
   - Get peer list
   - Join network

2. DHT (Distributed Hash Table)
   - Store domain mappings
   - No central DNS required
   - Resilient to failures

3. Gossip Protocol
   - Share peer information
   - Health monitoring
   - Load balancing

2.3 NAT Traversal

The NAT Problem
===============

Most home networks use NAT:
  - Internal IP: 192.168.1.x
  - External IP: Single public IP
  - Incoming connections blocked

Need to punch through NAT.


NAT Types
=========

Open (10%):
  [OK] Direct connection possible
  [OK] No special handling needed

Full Cone (30%):
  [OK] Port forwarding works
  [OK] Predictable ports
  [i] Some setup needed

Restricted (40%):
  [i] Hole punching required
  [i] Coordination needed
  [OK] Usually works

Symmetric (20%):
  [!] Most restrictive
  [!] Different port per connection
  [!] Relay required


Traversal Techniques
====================

1. STUN (Session Traversal)
   - Discover external IP/port
   - Works for most NATs
   - Low overhead

2. TURN (Relay)
   - Use relay server
   - Works for all NATs
   - Higher latency

3. ICE (Interactive Connectivity)
   - Try all methods
   - Select best option
   - Automatic fallback


WIA Implementation
==================

Automatic detection:
  1. Detect NAT type
  2. Try direct connection
  3. Try hole punching
  4. Fallback to relay

User sees:
  "Your site is live!"
  (All complexity hidden)

2.4 WIA DNS

Domain System
=============

Traditional DNS:
  - Centralized servers
  - Annual renewal fees
  - Can be seized/blocked
  - Dependent on registrar

WIA DNS:
  - Distributed across network
  - Free forever
  - Censorship resistant
  - You control it


Domain Format
=============

yourname.wia.home
  - Personal site
  - Portfolio
  - Blog

yourname.wia.shop
  - E-commerce
  - Business site
  - Product catalog

yourname.wia.blog
  - Blog focused
  - Content site
  - Publications

yourname.wia.page
  - Single page
  - Landing page
  - Project page


Registration
============

Register domain:
  1. Choose name
  2. Generate keypair
  3. Sign registration
  4. Broadcast to network

Ownership:
  - Proven by cryptographic key
  - No central authority
  - Cannot be taken away


Custom Domain (Optional)
========================

Already have domain?
  - Point DNS to WIA network
  - Both addresses work
  - Gradual migration possible

2.5 Content Distribution

CDN Without CDN
===============

Traditional CDN:
  - Edge servers worldwide
  - Expensive ($50-500/month)
  - Provider-dependent

WIA P2P Distribution:
  - Peers cache popular content
  - Automatic distribution
  - Free and decentralized


How It Works
============

1. First Request
   Visitor -> Your PC -> Content

2. Subsequent Requests (same area)
   Visitor -> Nearby peer (cached) -> Content

3. You Go Offline
   Visitor -> Multiple peers (cached) -> Content


Cache Strategy
==============

Hot content (popular):
  - Cached on many peers
  - Fast delivery
  - High availability

Cold content (rare):
  - Direct from origin
  - On-demand caching
  - Still accessible


Benefits
========

[OK] Fast delivery (nearby peers)
[OK] High availability (redundancy)
[OK] Free (no CDN costs)
[OK] Scales automatically
[OK] Works even when you sleep

Chapter Summary