University:
York University
Course:
AP/ITEC 1610 | Introduction to Computer Programming
Academic year:

2023
Views:

318

Pages:

2
Author:

Nick T.

Link Layer →hup to hop transfer Datagrams can be transferred by different protocols foreach link Links: wired, wireless, LANS Link layer has responsibility of transferring datagram from one node to physically adjacent node Datagram comes from network layer! encapsulated into frame to link layer-gets in layer 2 MAC Address medium access control • Unique identifier assigned to a network interface controller (NIC card) on a device 48 bit code ID • Used for communication within a network segment Lo common in ethemet, wi-fi, bluetooth •Locally used to transfer frame & between physically connetted interfaces within the same network. Services Framing, link access - encapsulate datagram into frame, add header and trailer -MAC address in frame header -channel access if shared medium Delivery between adjacent nodes (reliable?) -Emor chedes seldom used on links with low bit-error -Wireless links have higher error rates Flow control Pacing between sender (receiver Error detection - errors caused by noise receiver either signals retransmission or drops frame Error Comection receiver identifies and corrects bit error(s) without retransmission Half/full duplex -Half: nudes at both ends can transmit but not at the same time Implementation In network interface card or on a chip Cumbination of hardware, software, Armware