2022 EDSIG Proceedings: Abstract Presentation

Introductory routing concepts can be a challenge to grasp for students of all ages. In our lesson, The Internet of Strings, we created a kinesthetic activity that allows students to grasp basic shortest path routing algorithms while encountering real-world scenarios on the actual internet. Best of all, the supplies needed for the activity are available for instructors at little or no cost!

The setup for the activity begins with an overview of the post office; post offices are like routers in that smaller/regional offices service small areas while ‘linking’ to larger distribution centers, creating a network across the United States. Much like a post office uses zip codes, we draw parallels to the IP addressing system that is in place with the internet.

The classroom is set up with numbered stations, or routers, where the students start. At each router, strings are used to connect to other routers across our network—the connections between each router are simply twine and some tape to secure the connections to the table. Each link is labeled with the ‘destination’ router on the other end of the string, much like a router on the internet is aware of the address of the connected peer.

Students are then given a film canister with a destination number and a small clip that allows the packet to be hooked to their network ‘connection’. This canister becomes their “packet.” The students, acting as routers, must determine the most efficient path for their packet to make it to the destination and deliver the packet to the next router on the link. Once the student has delivered the packet to the next router, the student returns to their station, much like routers on the internet- once we’ve delivered the packet to the next hop, our job is done.

Once the packet makes it to the destination, opening the canister reveals that “data” (in the form of candy or a written message) has been encapsulated within the packet.

Much like the real-world internet, the Internet of Strings may be ripe with complications! Routers may go offline (an unattended station), which requires the network to reconverge to find a new path. Links between routers may go offline, and fiber optic cables are constantly cut! In our scenario, scissors achieve the same result. Additionally, routers may become overwhelmed, introducing latency on the network. These scenarios make excellent points for reflection with students in the classroom.

Overall, the key objectives are essential for instructional staff to understand the context of the lesson. In concluding this activity, students should be able to: • Identify the role that routers serve while functioning on the internet • Apply shortest path algorithms to determine the most efficient path that a packet should take when visually routed in a graph • Determine how to adapt the shortest path algorithm in a situation when the structure of a routing map/graph changes

Thursday at 11:35 am