LLC-Provides an interface to the upper layers
MAC- Controls the placement of a frame on the medium
LLC-Remains relatively independent of the physical equipment
MAC-Adds a frame delimiter
MAC-Provides a unique source and destination address
Concept Questions
1. The success of Ethernet is due to the following factors:
• Simplicity and ease of maintenance
• Ability to incorporate new technologies
• Reliability
• Low cost of installation and upgrade
2. Data encapsulation provides three primary functions:
• Frame delimiting
• Addressing
• Error detection
3. Each Ethernet frame contains a trailer with a cyclic redundancy check (CRC) of the frame contents. After reception of a frame, the receiving node creates a CRC to compare to the one in the frame. If these two CRC calculations match, the frame can be trusted to have been received without error.
Vocabulary Exercise: Matching
d.Half Duplex- Only one station at a time can transmit
c.Hub- Concentrates connections, allowing the network to see a group of nodes as a single unit
b.10BASE2- Uses 185 meters of thin coaxial cable
f.Switch- Isolates each port and sends a fram only to its proper destination
e.Full Duplex-Both ends of a conneciton ca send at the same time
a.10BASE5- Uses 500 meters of thick coaxial cable
Concept Questions
1. Half duplex is a type of communication that allows for one station to recieve while the other station is transmitting while the full duplex allows for receipt and transmission simultaneously.
2. The early implementations of Ethernet were deployed in a low-bandwidth LAN environment where access to the shared media was managed by CSMA, and later CSMA/CD. In additional to being a logical bus topology at the Data Link layer, Ethernet also used a physical bus topology. This topology became more problematic as LANs grew larger and LAN services made increasing demands on the infrastructure. The physical topology was also changed to a star