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The Four Addressing Scopes

Run the The Four Addressing Scopes MicroSim Fullscreen

About This MicroSim

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This MicroSim is built with p5.js and is width-responsive, so it adapts to the width of the page or container it is embedded in.

How to Use

Use the controls in the panel below the drawing area to explore the concept. Adjust the sliders, toggle the options, and step through the stages to see how each change affects what is shown.

Specification

The full specification below is extracted from Chapter 3: Network Architecture and Layered Models.

Type: microsim
**sim-id:** addressing-scopes-comparison<br/>
**Library:** p5.js<br/>
**Status:** Specified

Build an interactive MicroSim that animates the four addressing scopes side by side, letting students click each to see its delivery pattern.

Canvas: 960 px wide by 600 px tall, responsive down to 360 px. A 100 px control panel sits below.

Layout:

- The canvas is split into four quadrants, each ~480 × 300 px, labeled "Unicast", "Multicast", "Broadcast", "Anycast".
- Each quadrant contains the same simple topology: 1 sender on the left, 1 router in the middle, and 6 receivers arranged on the right.
- All four quadrants are inactive by default; only one animates at a time, selected by clicking its label or via a tab control.

Animation per quadrant:

- **Unicast**: the sender emits a single packet (honey-amber dot) addressed to receiver 3. The router forwards it; only receiver 3 lights up green; the others stay dim.
- **Multicast**: the sender emits a single packet addressed to a multicast group. The router replicates it at the branching point and forwards copies to receivers 2, 4, and 6 (a subset, the multicast group). Those three light up green; the others stay dim. Annotate "Group members only".
- **Broadcast**: the sender emits a single packet with broadcast destination. The router replicates and forwards to all six receivers; all six light up green.
- **Anycast**: three receivers (1, 3, 5) share the same anycast address; the others have unrelated addresses. The sender emits a single packet to the anycast address. The router selects the "closest" of the three (e.g., receiver 1 based on shortest path), and only that one lights up. A separate animation step shows the same packet, this time arriving via a different ingress router, being delivered to receiver 5 instead — demonstrating that the chosen receiver depends on routing topology.

Controls panel:

- Tab buttons: Unicast / Multicast / Broadcast / Anycast (one selected at a time).
- Step / Play / Reset buttons.
- "Topology source" toggle for the anycast animation: switches between two ingress routers to show that anycast routing depends on origin.

Visual style:

- Sender: hexagon in honey amber.
- Router: octagon in slate.
- Receivers: circles, default dim gray, lit receivers in vibrant green (#43a047).
- Packets: small filled circles in the layer color of the demonstration.
- A small legend in each quadrant summarizes the scope's rule.

Learning objectives:

- (Bloom — Remembering) Students recall that unicast goes to one, multicast to a group, broadcast to all on the link, anycast to the closest of many.
- (Bloom — Analyzing) Students compare the network resource cost of multicast versus unicast for delivering the same data to many receivers.
- (Bloom — Evaluating) Students judge which addressing scope is appropriate for a given application (live sports broadcast → multicast; DNS root server lookup → anycast).

The MicroSim should be implemented in pure p5.js with no external dependencies, using the existing MicroSim CSS theme. Animations should be smooth at 60 FPS and pause on tab switch.

Iframe Embed Code

You can add this MicroSim to any web page by adding this HTML:

<iframe src="https://dmccreary.github.io/networking/sims/addressing-scopes-comparison/main.html"
        height="502px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Learning Objective

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Bloom Taxonomy Level

Remember

Suggested Classroom Use

  1. Predict — Ask students to predict the behavior before they interact.
  2. Explore — Have students manipulate the controls and observe the results.
  3. Explain — Ask students to explain, in their own words, what they observed and how it connects to network architecture and layered models.

References