Networking and Data Communication

General Interactive Tools

GTools

General Tools

Cross-Layer Concepts · Performance · Analysis · Simulations

1 Tool

Explore the four sources of network delay with live formulas, shared parameters, and animations showing where each delay occurs.

Processing and output-queue delay

Transmission delay with capacity-scaled link

Propagation delay by distance and medium

Combined nodal-delay calculation

TCP / IP Stack — Interactive Tools

5 Layer

Application Layer

HTTP · DNS · SMTP · FTP · TLS · Client-Server & P2P Models

Coming Soon

No interactive tools planned for this layer

Application layer protocols are well-suited to lecture and discussion — the concepts of request/response, DNS resolution, and session management tend to land without requiring animated visualizations. These topics are covered in CS339 through lecture, Wireshark labs, and hands-on exercises.

HTTP / HTTPS DNS SMTP / IMAP FTP TLS Handshake Client-Server Model P2P Architecture CDNs

4 Layer

Transport Layer

TCP · Flow Control · Congestion · Seq/Ack · SYN/FIN Handshakes

1 Tool

TCP Transport

TCP Full Visualizer

End-to-end TCP simulation with sender/receiver buffers, sliding window, congestion control phases, and live packet exchange. Covers the complete connection lifecycle.

Three-way SYN handshake & FIN teardown

Seq / Ack number tracking in real time

Flow control — rwnd, sender buffer drain

Congestion control — slow start, AIMD, ssthresh

Packet loss injection & retransmit simulation

3 Layer

Network Layer

CIDR · Subnetting · Routing Tables · LS / DV · DHCP · NAT

5 Tools

IP Addressing & Subnetting

CIDR Teaching Tool

Explore IP addresses at the bit level. Understand CIDR notation, subnet masks, block sizes, and address allocation through live interactive visualizations.

32-bit IP and mask display with decimal octets

8 stat cards with step-by-step calc overlays

Compare tab — same-subnet AND bit math

Aggregation tab — route summarization

12-step guided tour from first principles

Network Design & NAT

Subnet Topology Builder

Build dynamic topologies with routers, subnets, and hosts. Visualize packet routing, NAT / PAT translation tables, and /30 point-to-point links on an interactive canvas.

Drag-and-drop topology canvas with auto-layout

Animated packet simulation host-to-host

NAT / PAT with live translation table

Echo-back packet with port mapping

Per-node bit display and calc overlays

Forwarding & Routing Tables

Router Visualizer

Interactive router with live forwarding table lookups, longest-prefix matching, and per-interface inspection. Trace how a datagram is forwarded hop-by-hop.

Forwarding table with longest-prefix match

Per-interface IP & MAC inspection

Live packet trace with TTL decrement

Static route configuration walkthrough

Link-State & Distance Vector

Routing Algorithm Visualizer

Step through Dijkstra (Link-State) and Bellman-Ford (Distance Vector) algorithms on configurable network graphs. Watch routing tables converge in real time.

Dijkstra LS — step-by-step shortest paths

Bellman-Ford DV — iterative table updates

Animated graph with cost labels

Edit topology & rerun convergence

Graph & LS Topology

Graph Algorithm Visualizer

General-purpose graph visualizer for exploring network topology as a graph. Build arbitrary topologies, apply shortest-path algorithms, and visualize the LS flooding model.

Drag-and-drop node & edge construction

Weighted edge cost simulation

Shortest-path highlight & traversal trace

Supports LS flooding thought experiments

2 Layer

Link Layer

ARP · MAC Learning · Frame Flooding · VLANs · LAN Switching

1 Tool

LANs, ARP & MAC Learning

Link Layer Visualizer

Full LAN simulation covering switch MAC table learning, ARP request/reply cycles, broadcast flooding, VLAN isolation, and inter-subnet routing via a gateway. Step through each frame hop with detailed inspection panels.

L2 MAC address learning — source observation on ingress

ARP broadcast, unicast reply, cache population

Unknown-destination flood with selective delivery

VLAN enforcement — cross-VLAN drop demonstration

Routed path — frame re-encapsulation at each hop

1 Layer

Physical Layer

Signals · Encoding · Copper · Fiber · Wireless · Bandwidth · Attenuation

Coming Soon

No interactive tools planned for this layer

Physical layer concepts — signal propagation, encoding schemes, and transmission media — are well served by lecture, diagrams, and lab exercises. CS339 covers these topics as foundational context before moving up the stack, where the interactive tools in this collection are focused.

Bit Transmission Signal Encoding Copper / Twisted Pair Fiber Optic Wireless / RF Bandwidth Attenuation Nyquist / Shannon