The Physical Layer (TCP/IP) Flashcards
The physical layer (1st layer of the TCP/IP 5 Layer Network Model)
What are the two categories for cables?
Copper and Fiber-optic cables
How is data communicated through copper cables?
Different voltages represent different binary bits
What is the physical makeup of Copper cables?
Copper cables have strands of copper twisted inside them
What are the most common forms of copper twisted-pair cables used in networking?
Cat5, Cat5e, and Cat6
What is Crosstalk with respect to cables?
Crosstalk is when an electrical pulse on one wire is accidently detected on another wire
What is the physical makeup of Fiber-optic cables?
Fiber cables contain individual optic cables, which are tiny tubes made of glass about the width of a human hair
How is data communicated through fiber cables?
Pulses of light represent binary values
What is a network Hub?
A physical layer device that allows for connections from many computers at once
How do network Hubs operate?
All the devices connected to a hub will end up talking to all other devices at the same time. It’s up to each system connected to the hub to determine if the incoming data was meant for them, or to ignore it if it isn’t
What is a Collision Domain?
A network segment where only one device can communicate at a time. If multiple systems try sending data at the same time, the electrical pulses sent across the cable can interfere with each other. This causes these systems to have to wait for a quiet period before they try sending their data again
What is a network Switch?
A data link (layer 2) device that allows for connections from many computers at once
How do network Switches operate?
Switches can inspect the Ethernet protocol data being sent around a network, determine which system its for and sent it only to that system
What is a single network referred to as?
Local Area Network (LAN)
What is a network Router?
A Layer 3 device that knows how to forward data between independent networks
How do network Switches operate?
A Router can inspect IP data to determine where to send it to. Routers store internal tables containing information about how to route traffic between lots of different networks all over the world