Computer Networks 1 (CSE 231) Quiz

Study Notes

Security and privacy concerns, interference with other wireless devices, battery life, power consumption, and compatibility issues with different devices are challenges of BAN.
Examples of BAN include wearable devices (smartwatches, fitness trackers), implantable devices (pacemakers, cochlear implants), and smart clothing.
BANs typically refer to the network made by medical wearable sensors with connectivity placed on, embedded in, or carried near the human body.
They usually use Bluetooth, RFID, and very low energy communication defined by IEEE 802.15.6.
BANs are used for tracking or supporting biomedical functions (e.g., pacemakers with wireless capabilities).
Benefits of BAN include real-time monitoring of vital signs, remote health monitoring, early detection of diseases, monitoring athletes’ performance in sports, and preventing injuries.

PANs allow devices to communicate over the range of a person.
A common example is a wireless network that connects a computer with its peripherals.
Usually, Bluetooth is used for this purpose.
In the simplest form, Bluetooth networks use the master-slave paradigm.
The system unit (the PC) is normally the master, talking to the mouse, keyboard, etc., as slaves.

A LAN is a privately owned network that operates within and nearby a single building.
LANs are widely used to connect personal computers and consumer electronics to share resources and exchange information.
When LANs are used by companies, they are called enterprise networks.
Typically, wired LANs run at speeds of 100 Mbps to 10 Gbps, have low delay (microseconds or nanoseconds), and make very few errors.

Each computer network is designed to cover a certain area, serving a specific purpose or entity.
The area is sometimes measured by the distance between processors of the devices.

A MAN is a computer network that connects computers within a metropolitan area (a single large city, multiple cities and towns, or any given large area with multiple buildings).
Like WANs, a MAN is made up of interconnected LANs.
Because MANs are smaller, they are usually more efficient than WANs.
MANs typically combine the networks of multiple organizations, instead of being managed by a single organization.
Most MANs use fiber optic cables to form connections between LANs.
A MAN will run on "dark fiber" — formerly unused fiber optic cables that are able to carry traffic.

Parameter comparison: maintenance and design, speed, delay in propagation, and fault tolerance between LAN, MAN, and WAN.

A switch is a multiport bridge with a buffer and a design that can boost its efficiency and performance.
It is a data link layer device.
The switch can perform error checking before forwarding data, which makes it very efficient.
It does not forward packets that have errors and forward good packets selectively to the correct port only.
In other words, the switch divides the collision domain of hosts, but the broadcast domain remains the same.

Unmanaged switches: Simple plug-and-play design with no advanced configuration options.
Managed switches: Offer advanced configuration options such as VLANs, QoS, and link aggregation.
Smart switches: Similar to managed switches but easier to set up and manage.
Layer 3 switches: Operate at the Network layer and can route data between different network segments.
PoE switches: Have Power over Ethernet capabilities to supply power to network devices over the same cable that carries data.