data networking study guide
Format: 20-30 MC; 6pages of short answers
Review – labs
•
•
Travel over the internet; TCP/UDP is from end to end, IP is in the middle, between hops o Write email – this is data o Data is sent to the transport layer and is SEGMENTED, adds s/d PORT # and sequence number o Network layer turns these into packets with s/d ip address o Data link layer turns these into frames with s/d mac address for default gateway o Frames go to switch and switch checks source mac and learns it if it doesn’t o Switch checks destination mac (default gateway mac) and port floods if it doesn’t know
Switch does NOT OPEN frame; just reads frame because switch is same layer as frame o Switch forwards to router/default gateway o Router gets rid of frames and checks ip address, router REFRAMES with next hop dest. Mac address o Next device looks at dest mac address and see if mac address matches its mac address o Runs crc (cyclic redun. Check) and compares to fcf (frame check seq.), accepts frames and open them up o Packets are sent to network layer, sent to transport layer o Transport layer puts it in right order and passes to application layer
Intro/chapter 1 o Data storage – stored in digital binary o 8 bits make 1 byte o Know how to translate binary! o ASCII only supports English char set (0-127) o Duo bit/Unicode supports other languages with bigger char sets
UTF 8/16;
ASCII and UTF share same codes for 0-127
Larger than 127: leading byte has two or more 1’s followed by
0’s, continuation bytes start with 10 o Data sizes – what’s here
8 bits = 1 byte (B)
1 kilobyte = 1024 B
1 megabyte = 1,048,576 B
1 gigabyte = 1,073,741,824 B
1 terabyte = 10^12 B
Peta, exa, zetta, yotta o Hardware
Cpu – processing unit
o
o
o
o
o o o o Modem – de/modulate; digital analog phone lines
Network interface card – connects to network
Sound/video car – expands capabilities of computer
Buying a computer – starting
Review – labs
•
•
Travel over the internet; TCP/UDP is from end to end, IP is in the middle, between hops o Write email – this is data o Data is sent to the transport layer and is SEGMENTED, adds s/d PORT # and sequence number o Network layer turns these into packets with s/d ip address o Data link layer turns these into frames with s/d mac address for default gateway o Frames go to switch and switch checks source mac and learns it if it doesn’t o Switch checks destination mac (default gateway mac) and port floods if it doesn’t know
Switch does NOT OPEN frame; just reads frame because switch is same layer as frame o Switch forwards to router/default gateway o Router gets rid of frames and checks ip address, router REFRAMES with next hop dest. Mac address o Next device looks at dest mac address and see if mac address matches its mac address o Runs crc (cyclic redun. Check) and compares to fcf (frame check seq.), accepts frames and open them up o Packets are sent to network layer, sent to transport layer o Transport layer puts it in right order and passes to application layer
Intro/chapter 1 o Data storage – stored in digital binary o 8 bits make 1 byte o Know how to translate binary! o ASCII only supports English char set (0-127) o Duo bit/Unicode supports other languages with bigger char sets
UTF 8/16;
ASCII and UTF share same codes for 0-127
Larger than 127: leading byte has two or more 1’s followed by
0’s, continuation bytes start with 10 o Data sizes – what’s here
8 bits = 1 byte (B)
1 kilobyte = 1024 B
1 megabyte = 1,048,576 B
1 gigabyte = 1,073,741,824 B
1 terabyte = 10^12 B
Peta, exa, zetta, yotta o Hardware
Cpu – processing unit
o
o
o
o
o o o o Modem – de/modulate; digital analog phone lines
Network interface card – connects to network
Sound/video car – expands capabilities of computer
Buying a computer – starting