Download Receiving data

Receiving data
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Transform energy to bits
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Check the integrity of the frame (FCS/CRC)
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If the frame is corrupted → discard the frame
Check the destination MAC address
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Frame header and trailer destroyed
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Pass the packet to layer 3
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If that address does not exist in the machine → discard the packet
Network Layer (3)
Extract the segment
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Packet header is destroyed
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Pass the segment to layer 4
Calculate the checksum of the segment
If the checksum is not OK → discard the segment
Check the destination port number
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If the checksum is not OK → discard the packet
Check the destination IP address
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Data Link Layer (2)
Calculate the checksum of the packet
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If it is not the same as the machine/NIC address → discard the frame
Extract the packet
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Physical Layer (1)
Analize the frame (bits captured)
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Bits in memory (bytes) to form a frame
If the port number is not in the table → discard the segment
Extract the data (message)
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Segment header is destroyed
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Pass the message to the application
Transport Layer (4)
Voltage, bits and frames
1 1 0 1 0 0 0 1 0 1 1
2.5V
2.5V
… 1 1 0 1 0 0 0 1 0 1 1 ….
10101010…...101010111100111100101010101001 ……… 000111010010011010101010
10Base5
Reception of a frame
http://javax.mty.itesm.mx/networks1/cisco/index.html#5.1.2.3
https://www.youtube.com/watch?v=eMjpNuBRjk4
Transmitting data
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The station has a packet
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It already knows the destination IP address
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The packet is already built
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It needs to build the frame
Is the destination in the same LAN (subnetwork)?
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Yes. Destination MAC address is the intended final destination
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No. Destination MAC address is the default gateway
Get the corresponding destination MAC address
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Using ARP
Build the frame
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Encapsulating the packet