OSI Layers Flashcards
TDM
Time Division Multiplexing
● Each session takes turns, using time slots, to share the medium between all users
StatTDM
Statistical Time Division Multiplexing
● More efficient version of TDM, it dynamically allocates time slots on an as-needed basis instead of statically assigning
FDM
Frequency-Division Multiplexing (FDM)
● Medium is divided into various channels based on frequencies and each session is transmitted over a different channel
LLC
Logical Link Control (LLC) ▪ Provides connection services
Between MAC and Layer 3
▪ Acknowledgement of receipt of a message
▪ Flow control
● Limits amount of data sender can send at one time to keep receiver from becoming overwhelmed
▪ Error control
● Allows receiver to let sender know when an expected data frame wasn’t received or was corrupted by using a checksum
Asynchronous
● Uses start bits and stop bits to indicate when transmissions occur from sender to receiver
Synchronous
● Uses a reference clock to coordinate the transmissions by both sender and receiver
Broadband
● Divides bandwidth into separate channels
● Example:
o Cable TV
Baseband
● Uses all available frequency on a medium (cable) to transmit data and uses a reference clock to coordinate the transmissions by both sender and receiver
● Example: o Ethernet
MAC
Physical addressing
● Uses 48-bit address assigned to a network interface card (NIC) by manufacturer
● First 24-bits is the vendor code
● Second 24-bits is a unique value
RIP,OSPF,EIGRP
Routing Protocols
ICMP
Internet Control Message Protocol
Ping/Traceroute
Portless, Connectionless
Windowing
Adjusting the amount of data sent in each segment
Buffering
▪ Devices, such as routers, allocate memory to store segments if bandwidth isn’t readily available
▪ When available, it transmits the contents of the buffer
▪ If the buffer overflows, segments will be dropped
H.323
● Used to setup, maintain, and tear down a voice/video connection
NetBIOS
● Used by computers to share files over a network
