Data link control layer – often abbreviated simply to data link layer – is concerned with the transfer of data over a serial data link
The transmission mode may be either asynchronous or synchronous and based on either a character-oriented or a bit-oriented transmission control protocol
The data link layer is fundamental to the operation of all data communication applications
The data link layer needs to pack bits into frames, so that each frame is distinguishable from another. Our postal system practices a type of framing. The simple act of inserting a letter into an envelope separates one piece of information from another; the envelope serves as the delimiter.
Chapter 11 is named data link control, which involves flow and error control. It discusses some protocols that are designed to handle the services required from the data link layer in relation to the network layer.
The Data-Link layer is the protocol layer in a program that handles the moving of data in and out across a physical link in a network. The Data-Link layer is layer 2 in the Open Systems Interconnect (OSI) model for a set of telecommunication protocols.The Data-Link layer ensures that an initial connection has been set up, divides output data into data frames, and handles the acknowledgements from a receiver that the data arrived successfully. It also ensures that incoming data has been received successfully by analyzing bit patterns at special places in the frames....
Ensuring the sending entity does not overwhelm the receiving entity
Preventing buffer overflow
Time taken to emit all bits into medium
Time for a bit to traverse the link
Upon completion of this chapter, you will be able to: Explain the role of Data Link layer protocols in data transmission, describe how the Data Link layer prepares data for transmission on network media, describe the different types of media access control methods,... Inviting you to refer.
In this chapter, you learned to: Explain the role of Data Link layer protocols in data transmission, describe how the Data Link layer prepares data for transmission on network media, describe the different types of media access control methods,... Inviting you to refer.
Chapter 12 is devoted to access control, the duties of the data link layer that are related to the use of the physical layer. The main contents of this chapter include all of the following: Random access, controlled access, channelization.
Chapter 5 - Data link layer. After reading this chapter, the reader should be able to: Understand the functions of the data link layer, understand the concept of hop-to-hop delivery compared to host-to-host delivery and application-to-application delivery, understand the concept of access method and define different access methods used in LANs and WANs.
Computer Networking - Chapter 5: Link Layer and LANs understand principles behind data link layer services (error detection, correction, sharing a broadcast channel, link layer addressing, reliable data transfer, flow control); instantiation and implementation of various link layer technologies.
Data Link Layer. Learning Objectives
Upon completion of this chapter, you will be able to:
Explain the role of Data Link layer protocols in data transmission.
Describe how the Data Link layer prepares data for transmission on network media.
Describe the different types of media access control methods.
Identify several common logical network topologies and describe how the logical topology determines the media access control method for that network.
Explain the purpose of encapsulating packets into frames to facilitate media access. ...
Một nút gởi, một nút nhận, một kết nối: không cần media access control, không cần địa chỉ/e.g., dialup link, ADSL, ISDN. Một số giao thức DLC điểm - điểm: PPP( point- to- point protocol) HDLC : High level data link control .Packet framing: hỗ trợ nhiều giao thức, dồn kênh/phan kênh. Bit transparency .Error detection( không cần correction).Connection liveness
The media access control methods described by the Data Link layer protocols
define the processes by which network devices can access the network media
and transmit frames in diverse network environments.
High Frequency Data Link, or HFDL, is part of ARINC’s GLOBALink end-to-end communication system
The HFDL system is a segment of the Aircraft Communications Addressing and Reporting System (ACARS) used to exchange Airline Operational Control (AOC) and Air Traffic Control (ATS) messagesbetween aircraft end systems and corresponding ground-based stations.
GLOBALink/HF provides HF-based, air-to-ground digital communications with aircraft using ARINC 635 protocol.
The HFDL system uses the principles of geographic diversity and frequency diversity to optimize HF propagation...
In chapter 4, students will be able to: Explain how physical layer protocols and services support communications across data networks, build a simple network using the appropriate, explain the role of the data link layer in supporting communications across data networks, compare media access control techniques and logical topologies used in networks.
One of the major functions of the physical layer is to move data in the form of electromagnetic signals across a transmission medium. Whether you are collecting numerical statistics from another computer, sending animated pictures from a design workstation, or causing a bell to ring at a distant control center, you are working with the transmission of data across network connections. Chapter 3 discusses the relationship between data, which are created by a device, and electromagnetic signals, which are transmitted over a medium.
After explaining some ideas about data and signals and how we can use them efficiently, we discuss the characteristics of transmission media, both guided and unguided, in this chapter. Although transmission media operates under the physical layer, they are controlled by the physical layer.
Chapter 20 - Network layer: internet protocol. This chapter is devoted to the main protocol at the network layer that supervises and controls the delivery of packets from the source to destination. This protocol is called the Internet Protocol or IP.
Chapter 22 - Network layer: Delivery, forwarding, and routing. This chapter describes the delivery, forwarding, and routing of IP packets to their final destinations. Delivery refers to the way a packet is handled by the underlying networks under the control of the network layer. Forwarding refers to the way a packet is delivered to the next station. Routing refers to the way routing tables are created to help in forwarding.