Knowing Networks - Fundamentals - created from Mind Map

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OSI - 7 Layers

TCP/IP Model

THREE WAY HANDSHAKE TCP - Originating client sends out a packet with a SYN Flag and a Seq Number (X). The server replies with a SYN/ACK and own Seq Number (Y) and an acknowledgement of the client no X + 1. The Client will reply an ACK and increments its own seq number (X+1) and the sequence number of the server (Y+1). Connection created client can now start transmitting the data to the server. Connection remains until Client or Server sends a FIN packet or an RST packet to reset the connection / connection times out.

Well Know Ports: FTP: 20-21, SSH 22, Telnet 23, DNS 53, SMTP 25, HTTP 80, HTTPS 443

7 - Application

6 - Presentation

5 - Session

4 - Transport

3 - Network

2 - Data-Link

1 - Physical

Application

Transport

Internet

Network