Nt1310 Unit 5 Paper

Unit 4 Research Project: MAC Sublayer
The Media Access Control (MAC) is one of the sublayers contained in the Data Link Layer (DLL) of the Open Systems Interconnection (OSI) model. The MAC layer provides addressing and channel access control mechanisms, and works to transmit data from one Network Interface Card (NIC) to another across a connected network.
Carrier Sensed Multiple Access with Collision Detection (CSMA/CD) is the process used by non-switched Ethernet to detect a clear channel between devices helping to decrease the chance of data “colliding” during transmission. Utilizing MAC protocol, a devise will “listen” for other traffic between connected devises. If no traffic is detected, the device will pause (an added security against devices sending at the same time) and then send the data in the form of MAC protocol frames.
The PCI header includes the 6 byte destination address, 6 byte source address, and the 2 byte type field (the type field defines the protocol being used). The checksum consists of a 4 byte Cyclic Redundancy Check (CRC) used to error check the data for any dropped bits.
Any connected devise that reads the data transmitted will check the destination address; if the address does not belong to the devise, it will not read the rest of the frame. Once the intended recipient reads the frame, it will send a response to the source address; data received intact - continue, or data corrupt -