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Network layer communication - Coggle Diagram
Network layer communication
Operations at the network layer
Organize the addressing and delivery of packets a cross the network from host to destination
Includes directing packets from one router to another
Destination IP address is contained within the header of each packet
Address is stores for future routing purposes in routing tables along packets path to destination
All packets include an IP address
Data packets are referred to as an IP packet for TCP connection or a datagram for UDP connections
Header includes source IP address, size of packet, and which protocol will be used
Format of an IPv4 packet
MAde up of 2 sections, header and data
Header format is determined by IPv4 protocol
Size of IPv4 header ranges from 20 to 60 bytes
First 20 bytes are a set of fixed information, like the source and destination IP address, header length, and length of packet
Last set of bytes ranges from 0 to 40 and consists of options field
Includes IP routing information that devices use to direct packet
Length of data section varies greatly
Max size of IPv4 packet is 64,535 bytes
Contains message being transferred over internet, like website information and text
13 fields in an IPv4 packet
Version
Tells receiving devices what protocol the packet is using
IP header length(HLEN or IHL)
HLEN is the packets header length, indicates where the packet header ends and data begins
Type of service(ToS)
Prioritize packets for delivery to maintain quality of service on the network
Identification
Provides a unique identifier for all fragments of original IP packet to be reassembled later
Flags
Provides the device with more information about whether packet has been fragmented and if there are more fragments
Fragmentation offset
Tells routing devices where in the original packet fragment belongs
Time to Live(TTL)
Prevents data packets from being forwarded by routers indefinitely. IT makes a certain amount of ticks, and they incrementally go to 0 as the packet passes through routers
Protocol
Tells the receiving device which protocol is used for data portion
Header checksum
Contains a checksum that can be used to detect corruption if IP header in transit, corrupted packets are discarded
Options