Ethernet Basic Ch3 Flashcards
What’s difference between frames and packets?
Frames are used only at layer 2 Data link
Packets are used only at layer 3 Network
How many fields does a basic ethernet frame contain
5
Destination address
Source Address
Type
Data
FCS
Transition of frame starts with preamble
Frame can also contain extra filler called pad
What is a Preamble?
Gives receiving NIC time to know a frame is coming and to know exactly where the frame starts
What does the Type field do?
Helps receiving computer interpret the frame contents at a very basic level. Does not tell you if the frame contains higher level data such as email message or web page.
10 Base T
10: refers to speed = 10 Mbps
Base: refers to signaling type, base band, only contains one signal
T: Type of cable used. Twisted Pair
Cable Type: Requires cat 3 or higher two pair UTP cable RJ 45 connector
Distance: 100 meters between hub and node
Node Limit: No more 1024 nodes per hub
Star-bus topology, physical star, logical bus
CSMA/CD
Carrier Sense Multiple Access with Collision Detection
each node using network examines cable before sending data frame
Each machine has equal access to wire
What makes up a cross over cable?
One end of cable is wired according to TIA/EIA 568B standard.
Other is TIA/EIA 56A Standard
Enables two switches in early ethernet to communicate
What is a Cross Over Cable?
Reverses the sending and receiving pairs on one end of the cable
What is Spanning Tree Protocol (STP)?
Spanning Tree Protocol
Ethernet standard that was adopted to eliminate the problem of accidental switching loops
Switch sends special frames to sends special frames called Bridge Protocol Data Units prevents loops from happening in the first place
Define Bridge Protocol Data Unit (BPDU)
Bridge Protocol Data Unit
Special frame switches send to other switches
