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What is a protocol?. Protocol An agreement about how to do somethingThis enables computers and software built by different people to be able to communicate in the same languageExamples that we have seen:Hyper Text Transfer Protocol (HTTP) Web BrowserFile Transfer Protocol (FTP) File trans
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1. Protocol Example A quick word about protocols
because the Internet and everything it contains is built on them
2. What is a protocol? Protocol – An agreement about how to do something
This enables computers and software built by different people to be able to communicate in the same language
Examples that we have seen:
Hyper Text Transfer Protocol (HTTP) – Web Browser
File Transfer Protocol (FTP) – File transfer
Simple Mail Transfer Protocol (SMTP) – Email
Internet Protocol (IP) – Packets across the Internet
3. Human Protocols Sending a letter via the postal service
4. Computer Protocols Sending a packet via the network
5. Visual Comparison
6. Textual Comparison The address of the letter is the destination of the packet
The return address of the letter is the source of the packet
The content of the envelope is the payload of the packet
In both protocols, if you disobey the rules your message will not be received ?
7. Protocol Layers Protocols can be layered on top of other protocols to enable new ways of communicating
8. Example: Writing a letter A common protocol that is followed when writing a letter is:
9. Example: Writing a letter A common protocol that is followed when writing a letter is:
10. Example: Writing a Letter After following the protocol for writing a letter, I can use the protocol for sending a letter via the postal service:
11. Example: Writing a letter Thus, I have layered two protocols on top of each other.
The lower protocol provides a service used by the higher protocols.
12. Protocol Layering:The Internet is build this way Internet Protocol (IP) provides a way to deliver packets to a destination
13. TCP uses packets to maintain connections” across a network, and thus is layered above IP Protocol Layering:The Internet is build this way
14. UDP just sends or receives raw packets with a best-effort approach, also layered above IP Protocol Layering:The Internet is build this way
15. SSH, FTP, HTTP, SMTP and many more applications use TCP connections to communicate data back and forth Protocol Layering:The Internet is build this way
16. DNS, VoIP, and many more applications use UDP packets to communicate data Protocol Layering:The Internet is build this way
17. Summary of Internet/Networking The Internet
WWW + HTML
DNS
Clients/Servers and UNIXS
SSH and telnet clients
FTP client
Networking
Networks, Routers, and Packets
Connections
Hostnames, IP addresses, ports
Protocols
18. Remaining Topics PC Maintenance/Health
Disk cleanup, Scan disk, Defragging, Safe-Mode, Browser cleanup, Backup
PC Safety
Protection against/Removal of
Malware: Viruses, Worms, Spyware, Adware
Identity theft: Phishing schemes, key loggers, trojan horses
University resources for protection
19. Plan for the course 04/07 – PC Health, Teaching Survey
04/09 – PC Health (proj7 assigned)
04/11 – PC Health/Safety (hw7 assigned)
04/14 – PC Safety
04/16 – PC Safety (proj7 due)
04/18 – In-class written final (hw7 due)
04/22 – Make-up final from 8-9:50am
20. The Internet is built this way The Internet Protocol is near the bottom layer
It provides the rules for forming packets and passing them to their destination
Above that are the TCP / UPD protocols
Above that are the HTTP/FTP/SSH/SMTP protocols
21. Protocol Layers Thus we have the following protocol layers:
22. Computer Communication Protocol Layers Here are some common protocols found on the Internet and how they are layered: