1 IEEE Media Access Control FIS2166 Telecommunications for Information Systems March 25, 2008 Presented by: John Frederick Chionglo

2 Media Access Control Logical Link Control Physical The IEEE Standard and the OSI Reference Model Physical Data Link Network Transport Session Presentation Application Physical Logical Link Control Media Access Control IEEE LLC IEEE MAC MAC CSMA/CD MAC Ethernet IEEE PHY

3 IEEE Media Access Control Physical Media Access Control Logical Link Control Media Access Control (MAC) Logical Link Control Physical

MAC Normal Operation Logical Link Control Physical Logical Link Control TransmitFrame TransmitDataEncap TransmitBit StartTransmission transmitOK End Transmission Logical Link Control Frame Check Sequence (FCS) Client Data Source Address Destination Address Preamble Start Frame Delimiter (SFD) Length/Type Frame Normal Operation (Transmission)

MAC Deference Process Logical Link Control TransmitFrame TransmitDataEncap TransmitBit StartTransmission transmitOK End Transmission CarrierSense falsetrue readyTo StartTransmission deferON Deference Process InterFrameGap

MAC Collision Handling Logical Link Control TransmitFrame TransmitDataEncap TransmitBit StartTransmission transmitOK End Transmission CollisionDetect truefalse StartJamSendJam attempts += 1 Backoff TooManyAttempts (attempts > 16) excessiveCollisionError Collision Handling

MAC Transmit Frame Logical Link Control TransmitFrame TransmitDataEncap TransmitBit StartTransmission transmitOK End Transmission CollisionDetect truefalse StartJamSendJam attempts += 1 Backoff TooManyAttempts (attempts > 16) excessiveCollisionError Collision Handling CarrierSense falsetrue readyTo StartTransmission deferON Deference Process Normal Operation (Transmission) CSMA/CDMACSCDEthernet Xerox PARC Robert Metcalfe, David Boggs, Charles Thacker, and Butler Lampson

MAC Receive Frame return DisassembleFrame ReceiveLinkMgt truncateToOctetBoundary receiveOK, frameTooLong, frameCheckError, lengthError, alignmentError receiveDataValid ReceiveLinkMgt Procedure discard addressUnrecognized, frameTooSmall ReceiveDataDecap Function ReceiveFrame

9 IEEE Media Access Control Receive Frame Half Duplex Transmit Frame Full Duplex

10 References David, R., & Alla, H. (1992). Petri nets and Grafcet: tools for modeling discrete event systems. New York: Prentice Hall. Ethernet - Wikipedia, the free encyclopedia. (2008, February 25). Retrieved February 25, 2008 from LAN/MAN Standards Committee of the IEEE Computer Society. (2005). IEEE Std , Section One. New York, NY: The Institute of Electrical and Electronics Engineers, Inc. Retrieved January 30, 2008 from _section1.pdf _section1.pdf Metcalfe, R. M., Boggs, D. R., Thacker, C. P., & Lampson, B. W. (1977). Multipoint data communication system with collision detection. U.S. Patent Retrieved March 1, 2008 from

11 IEEE Media Access Control Thank You