📡 Hypothetical Network (HNet)

HNet is a routing emulator for a hypothetical hierarchical computer network. It models a system with an alternative, human-readable IP addressing format, designed around geographic and administrative hierarchy.

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🌐 HNet Address Format

HNet uses a globally structured address format that is both machine-readable and human-friendly. Each address reflects a fixed geographic and administrative location.

[2 bytes]  Continent   — "EU", "AS", "NA", "AF", "SA", "OC", "AN"
[2 bytes]  Country     — ISO-3166 code, e.g., "RU", "US", "FR"
[4 bytes]  Provider    — Alphanumeric identifier, e.g., "MGTS", "NTNT"
[4 bytes]  Subnet      — Hex value, unique within the provider, e.g., 045A
[4 bytes]  Host        — Device identifier within the subnet, e.g., 1C2F

🔍 Example Address

NA:US:NTNT:045A:1C2F
^  ^  ^     ^     ^
|  |  |     |     └── Device 0x1C2F
|  |  |     └──────── Subnet 0x045A
|  |  └────────────── Provider "NTNT"
|  └───────────────── Country "US"
└──────────────────── Continent "NA"

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🧭 Routing Model

Each router (HNetRouter) follows this internal structure:

📘 Routing Table (routing_table)

Stores mappings from hierarchical address prefixes to interface identifiers:

HashMap<String, String> // prefix => interface_id

Prefixes are matched in order of decreasing specificity:

• EU:RU:MGTS:045A:1C2F
• EU:RU:MGTS:045A:*
• EU:RU:MGTS:*:*
• EU:RU:*:*:*
• EU:*:*:*:*

🔌 Interface Table (interfaces)

Maps interface IDs to neighboring routers (connected peers):

HashMap<String, HNetRouter> // interface_id => connected router

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🚚 Routing Algorithm

1. A packet is received by a router.
2. The router generates all prefix variants for the destination (from most to least specific).
3. It checks the routing_table for the first matching prefix.
4. It retrieves the associated interface_id and forwards the packet through the interface using interfaces.
5. The process repeats until the packet reaches its final destination or no route is found.

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by AndcoolSystems, 17 May, 2025