Data Communication

For communication to happen, there needs to be Data, Sender, Receiver.

Simplex: One directional data flow

graph LR Sender-->Receiver

Half-Duplex: Two-Way communication but not at the same time.

graph LR A-->B B-->A

Full-Duplex: Two-Way communication at the same time

graph LR A---B

Effectiveness

Delivery: The data actually reaches its intended recipient.
Accuracy: The data received is not altered in any way.
Timeliness: The data reaches the recipient with an acceptable delay.
No Jitter: The data arrives all at the same time.

Types of Connection

Point-to-point:
- Dedicated Link between two devices
- The entire bandwidth is reserved for the two devices
Multi-point:
- Multiple devices share a single link.
- Bandwidth is shared. (Channels)?

Physical Topology

Mesh Topology

graph LR A & B & C & D --- E A & C & D --- B A & D --- C A --- D

Each device is connected to all others through a point-to-point connection. In this topology, $\frac{n(n-1)}{2}$ connections are required for n devices.

Advantage:
- If a connection is broken, all other devices can continue communication.
Disadvantage:
- A lot of wiring required.

Star Topology

graph TD HUB[[HUB]]---A HUB---B HUB---C HUB---D

Advantage:
- n connections/wiring required.
- If a station/device is down, the network is intact.
Disadvantage:
- Centralized hub is a Single Point Of Failure. If it is down, the network breaks down.

Bus Topology

graph LR cable_start---tap_1([tap]) tap_1---tap_2([tap]) tap_2---tap_3([tap]) tap_3---cable_continued tap_1---A tap_2---B tap_3---C

Advantage:
- n connections/wiring required.
- If a station/device is down, the network is intact.
Disadvantage:
- The cable is still a Single Point Of Failure. If it is down, the network breaks down.

Ring Topology

graph LR A---B B---C C---D D---E E---A

Advantage:
- n connections required
- If one device is down, the network is intact (Iff there is two-way communication).
Disadvantage:
- For One-Way Connections, if one connection is down, all devices cannot communicate.

Hybrid

graph TD HUB[[HUB]]---tap_1([tap]) tap_1---tap_2([tap]) tap_2---tap_3([tap]) tap_3---. tap_1---Device_A tap_2---Device_B tap_3---Device_C HUB---tap_4([tap]) tap_4---tap_5([tap]) tap_5---tap_6([tap]) tap_6---.. tap_4---Device_D tap_5---Device_E tap_6---Device_F HUB---tap_7([tap]) tap_7---tap_8([tap]) tap_8---tap_9([tap]) tap_9---... tap_7---Device_G tap_8---Device_H tap_9---Device_I

Network Criteria

Reliability: Frequency of failure is minimal

Security:

Reliability: