[!NOTE] Chapter
TCP/IP
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Layer counts change based on course.
| Name | What | |
|---|---|---|
| Layer 1 | Physical Layer | Sends and receieves data over physical medium Cables,connectors,link speeds Copper,Fiber,Wireless,Antennas NICs |
| Layer 2 | Local Network Layer | Hop to Hop delivery on a local network Uses MAC to identify interfaces Ethernet and Wifi |
| Layer 3 | Internet Layer | End to End between hosts across networks Ip to identify Routers IP and ICMP |
| Layer 4 | Transport Layer | End to End between service-service Identify via ports Runs on communicating hosts UDP-TCP |
| Layer 5 (Layer 7 on OSI Model) | Application layer | Network comms to applications Browsing web,mails,transferring files HTTP/FTP/SMTP etc.. |
Every layer encapsulates data with a header.
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Data + L4 Header = Segment (TCP) or Datagram (UDP) Segment/Datagram + L3 Header = Packet Packet + L2 Header = Frame
Payload is everything it encapsulated before > Packets payload is Segment/Datagram Frame is what is being sent over the wire
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