Application-Physical Layer (Class 2)

5 Layer Model

Physical, Data Link, Network, Transport, Application

Application Layer

User's access to the internet

Application Layer Applications

Email Service, HTTP

Email services protocols

SMTP, IMAP, POP

Web Browsing Applications

HTTP

Physical Layer

Physical Connection between the sender and receiver

How does physical layer transmit

Using high and low voltage

What does the physical layer include

all hardware devices; computers, modems, switches; physical media; cables and satellites

Wired media

twisted-pair cable, coaxial cable, fiber-optic cable

Wireless media

Radio, microwave transmission, satellite

Differences between wired and wireless

having wires; speed (wired is faster)

Differences between cables

speeds, price, bandwidth

URL Address (application layer)

web browser; petfinder.com

URL Address (network layer)

Internet Protocol; xxx.xxx.xxx.xxx

URL Address (Datalink layer

Ethernet; 00-0c-00-f5-03-5a

Different types of URLs

EDU, COM, GOV, MIL, ORG

ICANN

Internet corporation for Asssigned names and Numbers

What does ICANN do

non profit organization; responsible for managing the assignment of network layer addresses (IP Addresses) and Application layer addresses (www.washington.edu)

DNS (Domain Name System)

translating human understandable URL names into machine understandable IP addresses

DNS Cache

Saves recent browser history of IP addresses

Command to show DNS cache

ipconfig /displaydns

MAC Address (Media Access control)

Physical address of a network adapter; unique to the device; Imbedded in NIC

MAC Address Length

48 bits (6 bytes)

MAC Address format

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