OSI Layers

Question 1

What does Layer 1 pertain to?

Answer 1

Physical layer. (Bits) The signal, the cabling, and connectors. Coax, Fiber, Wireless, Hubs Repeaters.

Question 2

What does Layer 2 pertain to?

Answer 2

Data link layer. (Frames). The “switching” layer. Ethernet, PPP, Switch, Bridge. MAC addresses.

Question 3

What does Layer 3 pertain to?

Answer 3

Network layer. (Packets) The “routing” layer. Encapsulation. Packets IP address, router, packet. IP, ICMP, IPSEC, IGMP

Question 4

What does Layer 4 pertain to?

Answer 4

Transport layer. (Segments). End to end connections. TCP & UDP port numbers

Question 5

What does Layer 5 pertain to?

Answer 5

Session layer. Communication management between devices. Start, stop, and restart sessions. Synch & send to port. API’s, Sockets

Question 6

What does Layer 6 pertain to?

Answer 6

Presentation layer. Data formatting.. Encryption. Any data that needs to be encrypted or decrypted. ASCII. HTML, Java Script. GIF, JPEG. TLS, SSL.

Question 7

What does Layer 7 pertain to?

Answer 7

Application layer. The layer we see. Advertising services. Protocols are things like HTTP, FTP, SSH, DNS, SMTP, POP, IMAP, SNMP.