CH 5 MAC Sublayer

Addressing

The encapsulation process contains the Layer 3 PDU and also provides for data link layer addressing.

Frame delimiting

The framing process provides important delimiters that are used to identify a group of bits that make up a frame. These delimiting bits provide synchronization between the transmitting and receiving nodes.

In forming the frame, the MAC layer adds what?

a header and trailer to the network layer PDU.

A contention-based method means that?

any device can try to transmit data across the shared medium whenever it has data to send

Ethernet is a ?

contention-based method of networking.

The data encapsulation process includes what?

frame assembly before transmission, and frame disassembly upon reception of a frame.

Today's Ethernet LANs use ?

full-duplex switches, which allow multiple devices to send and receive simultaneously with no collisions.

The Carrier Sense Multiple Access/Collision Detection (CSMA/CD) process is used in ?

half-duplex Ethernet LANs to detect and resolve collisions.

Media access control

is responsible for the placement of frames on the media and the removal of frames from the media.

The second responsibility of the MAC sublayer is

media access control.

The underlying logical topology of Ethernet is a ?

multi-access bus; therefore, all nodes (devices) on a single network segment share the medium.

The use of frames aids in what?

the transmission of bits as they are placed on the media and in the grouping of bits at the receiving node.

Data encapsulation provides three primary functions:

Frame delimiting Addressing Error detection

Ethernet MAC sublayer has two primary responsibilities:

Data encapsulation Media access control

Error detection

Each frame contains a trailer used to detect any errors in transmissions.