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Group 6 - Coggle Diagram
Group 6
Describe the purpose and function of data layer link for transmission on specific media.
Enables upper layers to access the media
Controls how data is placed and received on the media
Exchanges frames between endpoints over the network media
Receives encapsulated data
Performs error detection and rejects any corrupt frame
Describe the purpose of ARP.
ARP usually translates the URLs to the IP addresses.
It can settle the IPv4 addresses to the MAC addresses.
It can give the dynamic IP configuration to a network device.
The internal private address is converted to the outer public address by ARP.
Explain how the ARP process in sending packet to a destination network.
It starts with the initiator sending an ARP Request as a broadcast frame to the entire network. This request must be a broadcast, because at this point the initiator does not know the target’s MAC address, and is therefore unable to send a unicast frame to the target.
Since it was a broadcast, all nodes on the network will receive the ARP Request. All nodes will take a look at the content of the ARP request to determine whether they are the intended target. The nodes which are not the intended target will silently discard the packet.
The node which is the target of the ARP Request will then send an ARP Response back to the original sender. Since the target knows who sent the initial ARP Request, it is able to send the ARP Response unicast, directly back to the initiator.
Describe the characteristics and functions of the data link frame.
Has 3 basic parts :
Header
Data
Trailer
contains the source data link address of the NIC card sending the frame
contains destination data link address of the NIC card receiving the frame
Characteristics :
Frame start and stop indicator flags
Addressing
Type
Control
Data
Error Detection
included after the data to form the trailer
contains the frame payload (i.e., packet header, segment header, and the data)
identifies special flow control services such as quality of service (QoS). QoS gives forwarding priority to certain types of messages. For example, voice over IP (VoIP) frames normally receive priority because they are sensitive to delay
identifies the Layer 3 protocol in the data field
indicates the source and destination nodes on the media
used to identify the beginning and end limits of the frame
Describe the basic characteristics of media access control methods on WAN and LAN topologies.
Contention-based access
All nodes operating in half-duplex complete for the use of the medium, but only one device can send at a time.
Controlled access
Each node has its own medium to use. These deterministic type of networks are inefficient because a device must wait its turn to access the medium.
Differentiate the roles of the MAC address and the IP addres
MAC address
identfies network devices on a local scale
layer 2 operation
physical address
hardcoded into the device at manufacturing
can't be changed
consists of 12 hexadecimal digits, usually grouped into six pairs separated by hyphens
IP address
controls how devices on the internet communicate on a global scale
layer 3 operation
logical address
assigned to device through software configurations
can be changed
IPv4 address consists of 32 bits, usually written as four decimal numbers, or a dotted quad
IPv6 address consists of 128 bits, with the first 64 reserved for network identification and the second 64 dedicated to identifying a device on the network. The address is written as eight sets of four hexadecimal digits separated by colons
. Explain why the IPv4 protocol requires other layers to provide reliability.
IP was designed as a basic protocol with low overhead and only provides functions necessary to deliver a packet from a source to a destination over the internet networks. Other functions such as tracking and managing the flow of the packets are performed by protocols in other layers. It is the OSI data link layer that takes the IP packet and prepares it for transmission.